diff --git a/src/lerobot/datasets/lerobot_dataset.py b/src/lerobot/datasets/lerobot_dataset.py
index 2bd277b3b..101eb20e7 100644
--- a/src/lerobot/datasets/lerobot_dataset.py
+++ b/src/lerobot/datasets/lerobot_dataset.py
@@ -307,6 +307,10 @@ class LeRobotDatasetMetadata:
                 latest_df = pd.read_parquet(latest_path)
                 df = pd.concat([latest_df, df], ignore_index=True)
 
+                # Memort optimization
+                del latest_df
+                gc.collect()
+
         # Write the resulting dataframe from RAM to disk
         path = self.root / DEFAULT_EPISODES_PATH.format(chunk_index=chunk_idx, file_index=file_idx)
         path.parent.mkdir(parents=True, exist_ok=True)
@@ -1048,6 +1052,10 @@ class LeRobotDataset(torch.utils.data.Dataset):
                 latest_df = pd.read_parquet(latest_path)
                 df = pd.concat([latest_df, df], ignore_index=True)
 
+                # Memort optimization
+                del latest_df
+                gc.collect()
+
         # Write the resulting dataframe from RAM to disk
         path = self.root / self.meta.data_path.format(chunk_index=chunk_idx, file_index=file_idx)
         path.parent.mkdir(parents=True, exist_ok=True)