Prior research has shown that surgical outcomes differ greatly by surgeon and facility, and a national program focuses on reducing this variability. This groundbreaking study has profound implications for improving the safety of surgery. At least 10 independent surgeon-reviewers examined video-recordings of 20 bariatric surgeons performing a laparoscopic procedure and rated the surgeons' skills, with a higher score representing better technical skills. Surgeons rated in the lowest quartile of surgical skill had more surgical complications, longer surgical times, and higher mortality within 30 days of the surgery than those in the highest quartile of surgical skill. This study is the first to link practicing surgeons' directly observed technical skills to surgical safety outcomes. It underscores the need to broaden surgical improvement efforts beyond the use of systems approaches, such as teamwork and surgical checklists, and suggests incorporating technical skills assessment into programs that aim to either measure or enhance the quality and safety of care.