'Chemical cholecystectomy' has been proposed as an alternative to removal of the gallbladder. This study assessed cystic duct obliteration using bipolar electrocoagulation (with sham cannulation controls) and gallbladder mucosal treatment with tetracycline (or saline controls) in 29 mongrel dogs. Cystic duct obstruction was assessed by tube cholecystography at day 14, and epithelial damage by histology at day 42. Electrocoagulation by duct diathermy effectively occluded the cystic duct in 14 of 19 animals; however, this was associated with mucocele formation unless mucosal treatment with tetracycline was also performed. Immediate instillation of tetracycline after duct electrocoagulation produced only partial epithelial damage. The combination of duct electrocoagulation and delayed tetracycline instillation at 14 days produced complete destruction of all gallbladder epithelium and an effective chemical cholecystectomy.