OBJECTIVES: Evaluate the safety and efficacy of manipulation under anesthesia (MUA) for posttraumatic elbow stiffness. DESIGN: Retrospective, case series. SETTING: Single institution; level 1 trauma center. PATIENTS/PARTICIPANTS: Chart review of 45 patients over a 10-year period treated with MUA for posttraumatic elbow stiffness after elbow injuries treated both operatively and nonoperatively.None. MAIN OUTCOME MEASURES: Change in total flexion arc pre- to postmanipulation; time to manipulation; complications. RESULTS: Average time from most recent surgical procedure or date of injury to MUA was 115 days. Average premanipulation flexion arc was 57.9 degrees; average flexion arc at the final follow-up was 83.7 degrees. The improvement in elbow flexion arc of motion was statistically significant (P < 0.001). Post hoc analysis of the data revealed 2 distinct groups: 28 patients who underwent MUA within 3 months of their most recent surgical procedure (early manipulation), and 17 patients who underwent MUA after 3 months (late manipulation). Average improvement in elbow flexion arc in the early MUA group was 38.3 degrees (P < 0.001); improvement in the late MUA group was 3.1 degree. Comparison of improvement between the early and late MUA groups found a significant difference (P < 0.001) in mean flexion arc improvement from premanipulation to postmanipulation, favoring the early group. One patient had a complication directly attributable to MUA. Nineteen patients required additional procedures on the injured extremity after MUA. CONCLUSIONS: MUA is a safe and effective adjunct to improving motion in posttraumatic elbow stiffness when used within 3 months from the original injury or time of surgical fixation. After 3 months, MUA does not reliably increase elbow motion. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.