diff --git a/src/centimators/narwhals_utils.py b/src/centimators/narwhals_utils.py
index b506710..1848900 100644
--- a/src/centimators/narwhals_utils.py
+++ b/src/centimators/narwhals_utils.py
@@ -13,7 +13,7 @@ def _ensure_numpy(data, allow_series: bool = False):
     """Convert data to numpy array, handling both numpy arrays and dataframes.
 
     Args:
-        data: Input data (numpy array, dataframe, or series)
+        data: Input data (numpy array, dataframe, series, or PyTorch tensor)
         allow_series: Whether to allow series inputs
 
     Returns:
@@ -24,6 +24,14 @@ def _ensure_numpy(data, allow_series: bool = False):
     try:
         return nw.from_native(data, allow_series=allow_series).to_numpy()
     except Exception:
+        # Handle PyTorch tensors (including CUDA tensors)
+        try:
+            import torch
+            if isinstance(data, torch.Tensor):
+                # Move to CPU if on GPU, then convert to numpy
+                return data.detach().cpu().numpy()
+        except ImportError:
+            pass
         return numpy.asarray(data)