Background: There is a lack of evidence regarding the success of ulnar collateral ligament (UCL) revision reconstruction. Understanding outcomes after UCL revision reconstruction is important in clinical decision making for overhead athletes. Purpose: To evaluate return to play and patient-reported outcomes after UCL revision reconstruction. Study Design: Case series; Level of evidence, 4. Methods: All patients who underwent UCL revision reconstruction, attributed to retear of the ligament or pain, between June 2004 and July 2016 at 2 surgical centers were identified. Charts were reviewed for age, sex, date of primary and revision reconstruction, sport played, level of play, graft type, and complications. Patients were contacted by telephone to determine time to return to play, current level of participation, Conway score, Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow Score, and satisfaction. Results: Of the 65 consecutive baseball players who underwent revision UCL reconstruction, 40 (62%) were contacted at a minimum 22 months after surgery. Of these, 38 (95%) were pitchers and 2 (5%) were position players. Time to return to throwing was 6.2 ± 2.3 months (mean ± SD), and the KJOC score was 74.2 ± 20.7. Based on the Conway score, 50% (20/40) had an excellent result, indicating a return to the previous competition level for at least 1 year, and 30% (12/40) had a good result, indicating a return to a lower level for at least 1 year. For those who were able to return to competition, it took 12.7 ± 3.6 months. In pitchers, 47% (18/38) returned to their previous competition levels for at least 1 year, with a KJOC score of 73.7 ± 21.1. Pitchers were able to return to throwing at 6.3 ± 2.3 months and competition at 12.8 ± 3.7 months. Conclusion: Only half of baseball players undergoing UCL revision reconstruction were able to return to their previous levels of competition. Outcomes for revision reconstructions are not as promising as primary procedures. Baseball players should be cautioned that they may not return to their previous levels of play after a revision reconstruction.