diff --git a/python/python/lancedb/rerankers/mrr.py b/python/python/lancedb/rerankers/mrr.py
index 81a03c9ca..38f742bb8 100644
--- a/python/python/lancedb/rerankers/mrr.py
+++ b/python/python/lancedb/rerankers/mrr.py
@@ -97,7 +97,12 @@ class MRRReranker(Reranker):
             weighted_mrr = self.weight_vector * vector_rr + self.weight_fts * fts_rr
             final_mrr_scores[result_id] = weighted_mrr
 
-        combined_results = self.merge_results(vector_results, fts_results)
+        # With return_score="all", a row found by both searches must keep its
+        # `_distance` and its `_score`.
+        if self.score == "all":
+            combined_results = self._merge_and_keep_scores(vector_results, fts_results)
+        else:
+            combined_results = self.merge_results(vector_results, fts_results)
         combined_row_ids = combined_results["_rowid"].to_pylist()
         relevance_scores = [final_mrr_scores[row_id] for row_id in combined_row_ids]
         combined_results = combined_results.append_column(
diff --git a/python/python/lancedb/rerankers/rrf.py b/python/python/lancedb/rerankers/rrf.py
index 9c835a3ea..c9b54a5a7 100644
--- a/python/python/lancedb/rerankers/rrf.py
+++ b/python/python/lancedb/rerankers/rrf.py
@@ -54,8 +54,12 @@ class RRFReranker(Reranker):
             for i, result_id in enumerate(ids, 1):
                 rrf_score_map[result_id] += 1 / (i + self.K)
 
-        # Sort the results based on RRF score
-        combined_results = self.merge_results(vector_results, fts_results)
+        # Sort the results based on RRF score. With return_score="all", a row found
+        # by both searches must keep its `_distance` and its `_score`.
+        if self.score == "all":
+            combined_results = self._merge_and_keep_scores(vector_results, fts_results)
+        else:
+            combined_results = self.merge_results(vector_results, fts_results)
         combined_row_ids = combined_results["_rowid"].to_pylist()
         relevance_scores = [rrf_score_map[row_id] for row_id in combined_row_ids]
         combined_results = combined_results.append_column(
diff --git a/python/python/tests/test_rerankers.py b/python/python/tests/test_rerankers.py
index dd6cb4ab5..78b64613e 100644
--- a/python/python/tests/test_rerankers.py
+++ b/python/python/tests/test_rerankers.py
@@ -428,6 +428,38 @@ def test_rrf_multivector_ranks_each_result_list():
     assert result["_rowid"].to_pylist() == [2, 1, 3]
 
 
+@pytest.mark.parametrize("reranker_cls", [RRFReranker, MRRReranker])
+def test_rank_fusion_return_score_all_keeps_both_scores(reranker_cls):
+    # A row found by both searches must keep its vector `_distance` and its FTS
+    # `_score` when the reranker is asked to return all scores.
+    vector_results = pa.table(
+        {
+            "_rowid": pa.array([1, 2], type=pa.uint64()),
+            "text": ["a", "b"],
+            "_distance": pa.array([0.1, 0.2], type=pa.float32()),
+        }
+    )
+    fts_results = pa.table(
+        {
+            "_rowid": pa.array([2, 3], type=pa.uint64()),
+            "text": ["b", "c"],
+            "_score": pa.array([5.0, 4.0], type=pa.float32()),
+        }
+    )
+
+    result = reranker_cls(return_score="all").rerank_hybrid(
+        "query", vector_results, fts_results
+    )
+    rows = {row["_rowid"]: row for row in result.to_pylist()}
+
+    assert rows[1]["_distance"] == pytest.approx(0.1)
+    assert rows[1]["_score"] is None
+    assert rows[2]["_distance"] == pytest.approx(0.2)
+    assert rows[2]["_score"] == pytest.approx(5.0)
+    assert rows[3]["_distance"] is None
+    assert rows[3]["_score"] == pytest.approx(4.0)
+
+
 def test_rrf_reranker_distance():
     data = pa.table(
         {