Clinically severe obesity (CSO) is a surgically treated disease. The Roux-en-Y gastric bypass (RYGBP) has been used to treat patients with CSO and has resulted in an improvement in co-morbidities. We speculated that after a period of weight loss, patients would require less medication, resulting in cost-savings to both the patient and the insurance company, as well as an overall gain in health.A retrospective study was performed which involved the first 100 patients who had undergone RYGBP at a community-teaching hospital. Analysis of the data was conducted by the Wilcoxon signed rank test.64 patients met our inclusion criteria and had adequate follow-up data available. The mean BMI was 57 kg/m(2) (range 36.6- 85.4 kg/m(2)), the female to male ratio was 4:1 (51:13), and the mean age was 44 years (range 27-64). The average monthly medication expenditure was reduced from US dollars 317 (SEM 47.25, range US dollars 23.12-US dollars 1801.19) preoperatively, to US dollars 135 (SEM 35.35, range US dollars 0.00-US dollars 1122.72) postoperatively. This reduction is significant (P <0.01).Weight loss after RYGBP leads to a significant reduction in medication expenses. These medication savings offset the costs of the initial procedure and represent permanent financial savings for the patient and society.