Endoscopic papillotomy followed by the removal of stones with the Dormia basket is the treatment of choice in residual choledocolithiasis after cholecystectomy and in choledocolithiasis in patients with a high surgical risk. Nonetheless, the size of the stones may, occasionally, impede removal by this procedure. Mechanical lithotripsy may resolve this clinical situation. The authors present the results of this technique in 40 consecutive patients in whom the elimination of the stones was not possible by conventional methods and thus mechanical lithotripsy was performed. This procedure was found to be effective in 32 out of 40 patients (80%). In 22 cases (55%) lithotripsy was effective in one session performed during the first ERCP, 8 (20%) required two procedures and in 2 (5%) three sessions were necessary. In 9 cases the stones were spontaneously eliminated with lavage using physiologic serum or diluted contrast, in 6 the stones were extracted by lithotripsy, in 16 they were eliminated by a conventional Dormia basket and in the remaining case the Fogarty balloon was used. Lithotripsy could not be carried out in 8 out of the 40 patients (20%) due to inability to pick the stone up in 7 cases and because of the impossibility of breaking the stone up with the lithotripsy basket in the remaining case. No complications directly related to lithotripsy were observed. In conclusion, mechanical lithotripsy in an effective and safe therapeutic alternative in large size choledocolithiasis and can be performed during endoscopy.