Gallbladder carcinoma limited to the mucosa (pT1a) or muscularis proper (pT1b) with no lymph node metastasis (stage I) is defined as early carcinoma of the gallbladder. Eleven patients with early carcinoma of the gallbladder, treated by either simple or extended cholecystectomy (cholecystectomy plus wedge resection of the gallbladder bed of the liver and lymphadenectomy), were reviewed to determine the diagnostic capability and to clarify the rational resectional procedure for this stage of the disease. A definitive pre-operative diagnosis was made in only 2 patients with pT1b tumors. Most of the remaining 9 patients were diagnosed incidentally after cholecystectomy for polyps or stones. Among 7 patients with pT1a tumors, 5 underwent simple cholecystectomy and 2 underwent extended cholecystectomy. All 7 patients survived with a recurrence-free condition for 5 years or more following the operation. Two patients with pT1b tumors, however, died of a local recurrence or bile duct carcinoma following simple cholecystectomy. Two patients with pT1b tumors who were correctly diagnosed before the operation and underwent extended cholecystectomy survived without recurrence. It is concluded that patients with pT1a tumors can be successfully treated by simple cholecystectomy, while patients with pT1b tumors require extended cholecystectomy.