Background: Venous thromboembolism, a known complication of orthopaedic procedures, is thought to be more prevalent following hip surgery. Venous thromboembolism risk assessment and appropriate prophylaxis according to the American College of Chest Physicians guidelines has become the standard of care. However, it is accepted that venous thromboembolism prophylaxis is associated with potential adverse sequelae including hematoma, wound drainage, and infection. Little is known regarding the incidence of venous thromboembolism following periacetabular osteotomy and the necessity for and method of routine prophylaxis. Methods: A total of 1067 periacetabular osteotomies performed at six North American centers utilizing different methods of prophylaxis against venous thromboembolism were analyzed for type of prophylaxis and incidence of clinically symptomatic venous thromboembolism. Results: There were four cases of pulmonary embolus and seven cases of deep vein thrombosis. There were no reported deaths. The crude incidence of clinically symptomatic venous thromboembolism was 9.4 per 1000 procedures. Conclusions: The risk from chemoprophylaxis and the development of hematoma may be greater than the risk of clinically important venous thromboembolism in patients undergoing periacetabular osteotomy. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.