diff --git a/src/lerobot/common/wandb_utils.py b/src/lerobot/common/wandb_utils.py
index b782cd751..bdac7d4da 100644
--- a/src/lerobot/common/wandb_utils.py
+++ b/src/lerobot/common/wandb_utils.py
@@ -180,24 +180,32 @@ class WandBLogger:
                 self._wandb_custom_step_key.add(new_custom_key)
                 self._wandb.define_metric(new_custom_key, hidden=True)
 
+        batch_data = {}
         for k, v in d.items():
+            # Skip the custom step key here, it's added to the batch below.
+            if custom_step_key is not None and k == custom_step_key:
+                continue
+
+            if isinstance(v, list):
+                for i, elem in enumerate(v):
+                    if isinstance(elem, (int | float)):
+                        batch_data[f"{mode}/{k}_{i}"] = elem
+                continue
+
             if not isinstance(v, (int | float | str)):
                 logging.warning(
                     f'WandB logging of key "{k}" was ignored as its type "{type(v)}" is not handled by this wrapper.'
                 )
                 continue
 
-            # Do not log the custom step key itself.
-            if self._wandb_custom_step_key is not None and k in self._wandb_custom_step_key:
-                continue
+            batch_data[f"{mode}/{k}"] = v
 
+        if batch_data:
             if custom_step_key is not None:
-                value_custom_step = d[custom_step_key]
-                data = {f"{mode}/{k}": v, f"{mode}/{custom_step_key}": value_custom_step}
-                self._wandb.log(data)
-                continue
-
-            self._wandb.log(data={f"{mode}/{k}": v}, step=step)
+                batch_data[f"{mode}/{custom_step_key}"] = d[custom_step_key]
+                self._wandb.log(batch_data)
+            else:
+                self._wandb.log(data=batch_data, step=step)
 
     def log_video(self, video_path: str, step: int, mode: str = "train"):
         if mode not in {"train", "eval"}: