Background: Although the prognosis for gallbladder cancer (GBCA) improves with early diagnosis and aggressive surgical treatment, the management of patients with muscle layer invasion (T1b) remains controversial. This study aimed to analyze the optimal surgical approach for these patients. Methods: A database was queried for patients with early T1b GBCA treated at four Chilean hospitals. Patients were prospectively treated and registered by the same surgical team at each hospital. Clinical outcomes, including survival rates according to the type of surgery, were analyzed. Results: Between 1988 and 2023, 129 Chilean patients were pathologically diagnosed with T1b GBCA. Simple cholecystectomy (SC) was performed in 86 patients (66.7 %), while extended cholecystectomy (EC) was performed in 43 patients. The overall 5-year survival rate was 83 %, with no significant difference between SC and EC patients. Conclusion: Simple cholecystectomy demonstrated survival rates comparable to extended cholecystectomy for patients with T1b GBCA. More extensive resections did not improve the prognosis.