Nine patients with gallstones were treated by injection of methyl-tert-butyl-ether (MTBE) into the gallbladder. Complete or incomplete dissolution was observed in 5 of the 9 patients. The 4 failures were due to 2 main factors: poor selection of the patients (2 of them had pigment gallstones) and inadequate mixture with the solvent floating above the bile and gallstones. In addition, 4 complications were noted, all of them being resolved by medical treatment. A better selection of the patients and a more efficient technique of MTBE injection should improve these results.