ABSTRACTBACKGROUND:Despite its increasing popularity, laparoscopy is not the option for bariatric surgeries performed in the Brazilian public health system.AIMS:To compare laparotomy and laparoscopic access in bariatric surgery, considering aspects such as morbidity, mortality, costs, and length of stay.METHODS:The study included 80 patients who were randomly assigned to perform a Roux-en-Y gastric bypass. They were equally divided in two groups, laparoscopic and laparotomy. The results obtained in the postoperative period were evaluated and compared according to the Ministry of Health protocol, and later, in their outpatient returns.RESULTS:The surgical time was similar in both groups (p=0.240). The costs of laparoscopic surgery proved to be higher, mainly due to staplers and staples. The patients included in the laparotomy group presented higher rates of severe complications, such as incisional hernia (p<0.001). Costs related to social security and management of postoperative complications were higher in the open surgery group (R$ 1,876.00 vs R$ 34,268.91).CONCLUSIONS:The costs related to social security and treatment of complications were substantially lower in laparoscopic access when compared to laparotomy. However, considering the operative procedure itself, the laparotomy remained cheaper. Finally, the length of stay, the rate of complications, and return to labor had more favorable results in the laparoscopic route.