To study the efficacy of extracorporeal shock-wave lithotripsy (ESWL) of pancreatic duct stones, seventeen patients (mean age: 42 years) with recurrent attacks of abdominal pain as a result of chronic calcifying pancreatitis were treated with this method. In all cases, endoscopic removal of the stones proved impossible. When there was fragmentation, the remaining calculi and fragments either evacuated spontaneously, or attempts were made to extract them endoscopically, followed by flushing. In 13 patients (76%), fragmentation of stones was achieved, and 11 of these patients had dramatic pain relief directly after ESWL (65%). However, complete ductal clearance of stones was achieved in only seven patients (41%); at the last follow-up (12-59 months after ESWL, mean: 30 months), all seven were free of symptoms. Of the six patients with stone fragmentation without ductal clearance, three were operated on because of recurrent complaints. The only complication due to the procedure was an exacerbation of pancreatitis in one patient, which was treated conservatively. If pancreatic stones cannot be removed endoscopically, ESWL seems to be preferable to surgery, which may still be performed in case of failure. It seems important to achieve ductal clearance and not merely stone disintegration in order to obtain the desired long-term clinical effects.