We present 225 cases of routine operative cholangiography, utilizing a new squeeze-locking, split-loop clamp to secure the catheter inside the cystic duct plus an x-ray film technique using two different dye concentrations. No surgical or procedural difficulty was experienced in any of the 225 cases. Additional operating time for the procedure averaged under five minutes, with only one inconclusive x-ray film study. These results suggest that the new catheter clamp and the two-film technique provide a mechanical simplification of the procedure and that many of the causes of inconclusive x-ray film study have been eliminated.