Bariatric surgery is the most effective established intervention for weight loss in higher grades of obesity. Bariatric surgery is associated with approximately 30% body weight loss. Weight loss is associated with cardiovascular risk reduction especially in patients with higher grades of obesity. Thus early weight loss after an intervention may result in an early reduction of cardiovascular risk especially in patients at a higher risk. The effect of gender on weight loss after bariatric surgery is not clear and there is conflicting evidence. In this study we aimed to assess effect of gender on short term weight loss among Sri Lankan obese patients undergoing bariatric surgery. We did a retrospective analysis of medical records of 192 obese patients who underwent bariatric surgery at Colombo South Teaching Hospital, Sri Lanka. Overall 75.5% were females. The mean age was 38.2 (±10.2) years. Mean body weight and body mass index were 114.6 (± 22.4) kg, and 45.0 (± 6.7) kg/m2 respectively. Males lost more body weight than females at 1 week (14.0 vs 6.8 kg, p<0.001), 1 month (15.4 vs 9.8 kg, p<0.001), 3 months (27.3 vs 17.3 kg, p<0.001) and 6 months (34.2 vs 24.2 kg, p<0.005). The trend was similar for loss of body weight percentage at 1 week (9.5% vs 6.4%, p<0.001), 1 month (11.5% vs 9.2%, p=0.001), 3 months (19.6% vs 16.2%, p<0.001) and 6 months (25.4% vs 22.7%, p=0.05). In conclusion, Sri Lankan males lose significantly more weight than females during the first 6 months after bariatric surgery. At 6 months men lose an extra 10 kg when compared to their female counterparts. Thus Sri Lankan males may gain more cardiovascular and other health benefits in the short term than females due to bariatric surgery.