diff --git a/src/benchmark/executor.rs b/src/benchmark/executor.rs
index ac6577b..e450d40 100644
--- a/src/benchmark/executor.rs
+++ b/src/benchmark/executor.rs
@@ -15,6 +15,7 @@ use super::measurement::{Measurement, Measurements};
 
 use anyhow::{bail, Context, Result};
 
+#[derive(Clone, Copy)]
 pub enum BenchmarkIteration {
     NonBenchmarkRun,
     Warmup(u64),
diff --git a/src/benchmark/mod.rs b/src/benchmark/mod.rs
index ecf1302..4fc75fb 100644
--- a/src/benchmark/mod.rs
+++ b/src/benchmark/mod.rs
@@ -58,11 +58,12 @@ impl<'a> Benchmark<'a> {
         command: &Command<'_>,
         error_output: &'static str,
         output_policy: &CommandOutputPolicy,
+        iteration: executor::BenchmarkIteration,
     ) -> Result<Measurement> {
         self.executor
             .run_command_and_measure(
                 command,
-                executor::BenchmarkIteration::NonBenchmarkRun,
+                iteration,
                 Some(CmdFailureAction::RaiseError),
                 output_policy,
             )
@@ -85,7 +86,14 @@ impl<'a> Benchmark<'a> {
                             Append ' || true' to the command if you are sure that this can be ignored.";
 
         Ok(command
-            .map(|cmd| self.run_intermediate_command(&cmd, error_output, output_policy))
+            .map(|cmd| {
+                self.run_intermediate_command(
+                    &cmd,
+                    error_output,
+                    output_policy,
+                    BenchmarkIteration::NonBenchmarkRun,
+                )
+            })
             .transpose()?
             .unwrap_or_default())
     }
@@ -106,7 +114,14 @@ impl<'a> Benchmark<'a> {
                             Append ' || true' to the command if you are sure that this can be ignored.";
 
         Ok(command
-            .map(|cmd| self.run_intermediate_command(&cmd, error_output, output_policy))
+            .map(|cmd| {
+                self.run_intermediate_command(
+                    &cmd,
+                    error_output,
+                    output_policy,
+                    BenchmarkIteration::NonBenchmarkRun,
+                )
+            })
             .transpose()?
             .unwrap_or_default())
     }
@@ -116,11 +131,12 @@ impl<'a> Benchmark<'a> {
         &self,
         command: &Command<'_>,
         output_policy: &CommandOutputPolicy,
+        iteration: executor::BenchmarkIteration,
     ) -> Result<Measurement> {
         let error_output = "The preparation command terminated with a non-zero exit code. \
                             Append ' || true' to the command if you are sure that this can be ignored.";
 
-        self.run_intermediate_command(command, error_output, output_policy)
+        self.run_intermediate_command(command, error_output, output_policy, iteration)
     }
 
     /// Run the command specified by `--conclude`.
@@ -128,11 +144,12 @@ impl<'a> Benchmark<'a> {
         &self,
         command: &Command<'_>,
         output_policy: &CommandOutputPolicy,
+        iteration: executor::BenchmarkIteration,
     ) -> Result<Measurement> {
         let error_output = "The conclusion command terminated with a non-zero exit code. \
                             Append ' || true' to the command if you are sure that this can be ignored.";
 
-        self.run_intermediate_command(command, error_output, output_policy)
+        self.run_intermediate_command(command, error_output, output_policy, iteration)
     }
 
     /// Run the benchmark for a single command
@@ -165,10 +182,10 @@ impl<'a> Benchmark<'a> {
             )
         });
 
-        let run_preparation_command = || {
+        let run_preparation_command = |iteration: executor::BenchmarkIteration| {
             preparation_command
                 .as_ref()
-                .map(|cmd| self.run_preparation_command(cmd, output_policy))
+                .map(|cmd| self.run_preparation_command(cmd, output_policy, iteration))
                 .transpose()
         };
 
@@ -184,10 +201,10 @@ impl<'a> Benchmark<'a> {
                 self.command.get_parameters().iter().cloned(),
             )
         });
-        let run_conclusion_command = || {
+        let run_conclusion_command = |iteration: executor::BenchmarkIteration| {
             conclusion_command
                 .as_ref()
-                .map(|cmd| self.run_conclusion_command(cmd, output_policy))
+                .map(|cmd| self.run_conclusion_command(cmd, output_policy, iteration))
                 .transpose()
         };
 
@@ -206,14 +223,15 @@ impl<'a> Benchmark<'a> {
             };
 
             for i in 0..self.options.warmup_count {
-                let _ = run_preparation_command()?;
+                let warmup_iteration = BenchmarkIteration::Warmup(i);
+                let _ = run_preparation_command(warmup_iteration)?;
                 let _ = self.executor.run_command_and_measure(
                     self.command,
-                    BenchmarkIteration::Warmup(i),
+                    warmup_iteration,
                     None,
                     output_policy,
                 )?;
-                let _ = run_conclusion_command()?;
+                let _ = run_conclusion_command(warmup_iteration)?;
                 if let Some(bar) = progress_bar.as_ref() {
                     bar.inc(1)
                 }
@@ -234,7 +252,8 @@ impl<'a> Benchmark<'a> {
             None
         };
 
-        let preparation_result = run_preparation_command()?;
+        let benchmark_iteration = BenchmarkIteration::Benchmark(0);
+        let preparation_result = run_preparation_command(benchmark_iteration)?;
         let preparation_overhead = preparation_result.map_or(Time::zero(), |res| {
             res.time_wall_clock + self.executor.time_overhead()
         });
@@ -242,13 +261,13 @@ impl<'a> Benchmark<'a> {
         // Initial timing run
         let res = self.executor.run_command_and_measure(
             self.command,
-            BenchmarkIteration::Benchmark(0),
+            benchmark_iteration,
             None,
             output_policy,
         )?;
         let success = res.exit_status.success();
 
-        let conclusion_result = run_conclusion_command()?;
+        let conclusion_result = run_conclusion_command(benchmark_iteration)?;
         let conclusion_overhead = conclusion_result.map_or(Time::zero(), |res| {
             res.time_wall_clock + self.executor.time_overhead()
         });
@@ -289,7 +308,8 @@ impl<'a> Benchmark<'a> {
 
         // Gather statistics (perform the actual benchmark)
         for i in 0..count_remaining {
-            run_preparation_command()?;
+            let benchmark_iteration = BenchmarkIteration::Benchmark(i + 1);
+            run_preparation_command(benchmark_iteration)?;
 
             let msg = {
                 let t_wall_clock_mean = measurements.time_wall_clock_mean();
@@ -307,7 +327,7 @@ impl<'a> Benchmark<'a> {
 
             let res = self.executor.run_command_and_measure(
                 self.command,
-                BenchmarkIteration::Benchmark(i + 1),
+                benchmark_iteration,
                 None,
                 output_policy,
             )?;
@@ -321,7 +341,7 @@ impl<'a> Benchmark<'a> {
                 bar.inc(1)
             }
 
-            run_conclusion_command()?;
+            run_conclusion_command(benchmark_iteration)?;
         }
 
         if let Some(bar) = progress_bar.as_ref() {
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 826bace..e6832b2 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -1037,3 +1037,45 @@ fn windows_quote_before_quote_args() {
         .assert()
         .success();
 }
+
+#[test]
+fn hyperfine_iteration_env_var_in_prepare_and_conclude_commands() {
+    let tempdir = tempfile::tempdir().unwrap();
+    let output_path = tempdir.path().join("iteration output.txt");
+    let iteration = if cfg!(windows) {
+        "%HYPERFINE_ITERATION%"
+    } else {
+        "$HYPERFINE_ITERATION"
+    };
+    let command = |phase| format!(r#"echo {phase}:{iteration} >> "iteration output.txt""#);
+
+    hyperfine()
+        .current_dir(tempdir.path())
+        .arg("--runs=2")
+        .arg("--warmup=1")
+        .arg("--prepare")
+        .arg(command("prepare"))
+        .arg(command("benchmark"))
+        .arg("--conclude")
+        .arg(command("conclude"))
+        .assert()
+        .success();
+
+    let contents = std::fs::read_to_string(output_path).unwrap();
+    // cmd.exe's echo includes the space before the redirection operator.
+    let lines: Vec<&str> = contents.lines().map(str::trim_end).collect();
+    assert_eq!(
+        lines,
+        [
+            "prepare:warmup-0",
+            "benchmark:warmup-0",
+            "conclude:warmup-0",
+            "prepare:0",
+            "benchmark:0",
+            "conclude:0",
+            "prepare:1",
+            "benchmark:1",
+            "conclude:1",
+        ]
+    );
+}