Teamwork training programs continue to emerge despite past reviews suggesting their mixed effectiveness in changing behavior. This study conducted a multilevel evaluation of the TeamSTEPPS training program within an operating room service line and used a comparison unit at a separate facility. Following a 4-hour didactic program, the trained group demonstrated increases in the quantity and quality of presurgical procedure briefings and the use of teamwork behaviors observed during cases. Similar to past efforts, increases were also noted in perceptions of safety culture and teamwork attitudes. This study adds to the literature by employing a multilevel evaluation strategy, using a comparison unit, and observing actual behavior change that was attributed to the training. Patient outcomes were not part of the measurement strategy.