This study aims to assess the efficacy and safety of pharmacoprophylaxis regimens for venous thromboembolism (VTE) in patients undergoing bariatric surgery. A total of 15 studies were included. Low molecular-weight heparins (LMWH) and fondaparinux may be equally effective in reducing VTE risk (OR 1.02, 95% confidence interval [CI] 0.14-7.39). Pooled estimate suggested uncertain effects of augmented LMWH dosing on VTE prophylaxis compared with standard dosing (OR 0.57, 95% CI 0.07-4.39), but may increase major bleeding (OR 3.03, 95% CI 0.38-23.96). Very low-quality evidence showed an inconclusive effect of extended prophylaxis on VTE (OR 0.54, 95% CI 0.15-1.90) and major bleeding (OR 1.24, 95% CI 0.92-1.68) compared with restricted prophylaxis. Standard LMWH dosing may be effective and safe. Current evidences are insufficient to support extended prophylaxis.