Key PointsQuestionIs thromboprophylaxis with 10 mg of rivaroxaban for 7 and 28 days after bariatric surgery efficacious and safe?FindingsIn this randomized clinical trial, 272 patients undergoing bariatric surgery were assigned to 10 mg of rivaroxaban for 7 or 28 days. Overall, a single asymptomatic thromboembolic event (0.4%) occurred in a patient undergoing sleeve gastrectomy in the long prophylaxis group, and major bleeding and clinically relevant nonmajor bleeding events occurred in 5 patients (1.9%).MeaningThis trial found that thromboembolic prophylaxis with 10 mg of rivaroxaban was efficacious and safe after bariatric surgery.