The present study reports on morphological findings obtained from 15 patients who were submitted to percutaneous transhepatic contact dissolution of gallbladder concrements with methyl-tert.-butyl ether (MTBE) and--in case of slightly calcified gallstones (n = 10)--with ethylene diamine tetraacetic acid (EDTA). At a maximum intracystic catheter placement time of four days complete lysis was obtained in 12 patients. As could be depicted by CT, the solvents induced significant regional or disseminated chemical cholecystitis in the majority of all cases. However, these changes proved to be completely reversible within about five weeks. It is concluded that with certain types of gallstones contact dissolution can be an effective alternative therapeutic technique which, however, requires meticulous morphological controlling in view of the time-consuming treatment of calcified concrements.