ABSTRACT Objective: to evaluate the effectiveness and safety of laparoscopic cholecystectomies performed by residents of the first and second-year of a general surgery residency program. We studied the primary total cost of treatment and complication rates as primary outcomes, comparing the groups operated by senior and resident surgeons. Methods: this was a retrospective cohort study of patients who underwent laparoscopic cholecystectomy performed in a training hospital of large surgical volume in Brazil, in the period between June 1, 2018 and May 31, 2019. The study population comprised patients who underwent elective cholecystectomy due to uncomplicated chronic calculous cholecystitis or to the presence of gallbladder polyps with surgical indication. We divided the cases into three groups, based on the graduation of the main surgeon at the time of the procedure: first-year residents (R1), second-year residents (R2), and trained general surgeons (GS). Results: during the study period, 1,052 laparoscopic cholecystectomies were performed, of which 1,035 procedures met the inclusion criteria, with 78 (7.5%) patients operated on with the participation of first-year residents (R1), 500 (48.3%) patients with the participation of second-year residents (R2), and 457 (44.2%) with the participation of senior surgeons only. There was no difference in conversion rates, complications, and reporting of adverse events between groups. We observed a significant difference regarding hospitalization costs (p = 0.003), with a higher mean for the patients operated with the participation of R1, of US$ 2,671.13, versus US$ 2,414.60 and US$ 2,396.24 for the procedures performed by senior surgeons and R2, respectively. Conclusions: laparoscopic cholecystectomy with the participation of residents is safe, even in their first years of training. There is an additional cost of about 10% in the treatment of patient operated with the participation of first-year residents. There was no significant difference in the cost of the group operated by second-year residents.