diff --git a/tenacity/__init__.py b/tenacity/__init__.py
index c43475c4..079740f6 100644
--- a/tenacity/__init__.py
+++ b/tenacity/__init__.py
@@ -354,6 +354,7 @@ def begin(self) -> None:
         self.statistics["start_time"] = time.monotonic()
         self.statistics["attempt_number"] = 1
         self.statistics["idle_for"] = 0
+        self.statistics["delay_since_first_attempt"] = 0
 
     def _add_action_func(self, fn: t.Callable[..., t.Any]) -> None:
         self.iter_state.actions.append(fn)
diff --git a/tests/test_tenacity.py b/tests/test_tenacity.py
index 017e6831..0645a835 100644
--- a/tests/test_tenacity.py
+++ b/tests/test_tenacity.py
@@ -1354,6 +1354,23 @@ def test_retry_function_attributes(self) -> None:
                 self.fail("RetryError should have been raised after 1 attempt")
 
 
+class TestStatisticsKeys:
+    def test_delay_since_first_attempt_available_on_first_attempt(self) -> None:
+        """delay_since_first_attempt should be in statistics from the start."""
+
+        @retry(
+            stop=tenacity.stop_after_attempt(3),
+            retry=tenacity.retry_if_result(lambda x: x is None),
+        )
+        def succeeds_first_try() -> bool:
+            assert "delay_since_first_attempt" in succeeds_first_try.statistics
+            assert succeeds_first_try.statistics["delay_since_first_attempt"] == 0
+            return True
+
+        succeeds_first_try()
+        assert succeeds_first_try.statistics["delay_since_first_attempt"] == 0
+
+
 class TestRetryWith:
     def test_redefine_wait(self) -> None:
         start = current_time_ms()