diff --git a/src/agents/sandbox/snapshot_defaults.py b/src/agents/sandbox/snapshot_defaults.py
index afe7b9c8a8..1a54a14f72 100644
--- a/src/agents/sandbox/snapshot_defaults.py
+++ b/src/agents/sandbox/snapshot_defaults.py
@@ -4,7 +4,7 @@
 import sys
 import time
 from collections.abc import Mapping
-from pathlib import Path
+from pathlib import Path, PureWindowsPath
 
 from .snapshot import LocalSnapshotSpec
 
@@ -12,6 +12,16 @@
 _DEFAULT_LOCAL_SNAPSHOT_SUBDIR = Path("openai-agents-python") / "sandbox" / "snapshots"
 
 
+def _first_absolute_windows_env_path(env: Mapping[str, str], *names: str) -> Path | None:
+    for name in names:
+        value = env.get(name)
+        if not value:
+            continue
+        if PureWindowsPath(value).is_absolute():
+            return Path(value)
+    return None
+
+
 def default_local_snapshot_base_dir(
     *,
     home: Path | None = None,
@@ -27,8 +37,12 @@ def default_local_snapshot_base_dir(
     if resolved_platform == "darwin":
         base = resolved_home / "Library" / "Application Support"
     elif resolved_os_name == "nt":
-        local_app_data = resolved_env.get("LOCALAPPDATA") or resolved_env.get("APPDATA")
-        base = Path(local_app_data) if local_app_data else resolved_home / "AppData" / "Local"
+        env_base = _first_absolute_windows_env_path(
+            resolved_env,
+            "LOCALAPPDATA",
+            "APPDATA",
+        )
+        base = env_base if env_base is not None else resolved_home / "AppData" / "Local"
     else:
         xdg_state_home = resolved_env.get("XDG_STATE_HOME")
         base = Path(xdg_state_home) if xdg_state_home else resolved_home / ".local" / "state"
diff --git a/tests/sandbox/test_snapshot_defaults.py b/tests/sandbox/test_snapshot_defaults.py
index f752b4f859..2c34be69a7 100644
--- a/tests/sandbox/test_snapshot_defaults.py
+++ b/tests/sandbox/test_snapshot_defaults.py
@@ -45,7 +45,7 @@ def test_default_local_snapshot_base_dir_uses_macos_application_support(tmp_path
 
 
 def test_default_local_snapshot_base_dir_uses_localappdata_on_windows(tmp_path: Path) -> None:
-    local_app_data = tmp_path / "LocalAppData"
+    local_app_data = Path(r"C:\Users\me\AppData\Local")
     result = default_local_snapshot_base_dir(
         home=tmp_path / "home",
         env={"LOCALAPPDATA": str(local_app_data)},
@@ -56,6 +56,48 @@ def test_default_local_snapshot_base_dir_uses_localappdata_on_windows(tmp_path:
     assert result == local_app_data / "openai-agents-python" / "sandbox" / "snapshots"
 
 
+def test_default_local_snapshot_base_dir_uses_absolute_appdata_when_localappdata_is_relative(
+    tmp_path: Path,
+) -> None:
+    app_data = Path(r"C:\Users\me\AppData\Roaming")
+    result = default_local_snapshot_base_dir(
+        home=tmp_path / "home",
+        env={"LOCALAPPDATA": "relative-local", "APPDATA": str(app_data)},
+        platform="win32",
+        os_name="nt",
+    )
+
+    assert result == app_data / "openai-agents-python" / "sandbox" / "snapshots"
+
+
+def test_default_local_snapshot_base_dir_ignores_relative_windows_env_paths(
+    tmp_path: Path,
+) -> None:
+    home = tmp_path / "home"
+    result = default_local_snapshot_base_dir(
+        home=home,
+        env={"LOCALAPPDATA": "relative-local", "APPDATA": "relative-roaming"},
+        platform="win32",
+        os_name="nt",
+    )
+
+    assert result == home / "AppData" / "Local" / "openai-agents-python" / "sandbox" / "snapshots"
+
+
+def test_default_local_snapshot_base_dir_ignores_posix_absolute_localappdata_on_windows(
+    tmp_path: Path,
+) -> None:
+    home = tmp_path / "home"
+    result = default_local_snapshot_base_dir(
+        home=home,
+        env={"LOCALAPPDATA": "/tmp/localappdata"},
+        platform="win32",
+        os_name="nt",
+    )
+
+    assert result == home / "AppData" / "Local" / "openai-agents-python" / "sandbox" / "snapshots"
+
+
 def test_cleanup_stale_default_local_snapshots_removes_only_old_tar_files(tmp_path: Path) -> None:
     managed_dir = tmp_path / "snapshots"
     managed_dir.mkdir()