Objective To investigate the clinical efficacy of mini-plate fixation for ulnar coronoid process fracture via anteromedial approach.Methods A retrospective review was made on 28 cases of ulnar coronoid process fracture treated with open reduction and mini-plate fixation from April 2010 to December 2014.There were 18 males and 10 females,with age range of 21-60 years (mean,34.3 years).Causes of injury were falls in 21 cases and traffic accidents in 7 cases.According to the O' Driscoll classification,there were 14 cases of type Ⅰ,11 cases of type Ⅱ and 3 cases of type Ⅲ.Time from injury to operation was 2-10 d (mean,3.7 d).Reduction loss,fracture healing time and complications were documented.Elbow function was evaluated at the last follow-up by Mayo elbow performance score (MEPS) and Broberg & Morrey score.Results All cases were followed up for 12-25 months (mean,15.1 months).Restricted elbow activity was initiated one week after operation.Bone united in mean 10.6 weeks (range,8-14 weeks).No nerve injury or fracture redisplacement occurred.At the final follow-up,mean flexion was (124 ± 15)° (range,90°-140°),mean extension loss was (18 ± 20) °(range,0°-50°),mean pronation was (65 ± 18)°(range,40°-85°),and mean supination was (63 ±16)°(range,35°-85°),showing significant difference in comparison with the preoperative measure (P＜0.05).According to the MEPS,the results were excellent in 17 cases,good in 8,fair in 2 and poor in 1.According to the Broberg & Morrey score,the results were excellent in 16 cases,good in 8,fair in 3 and poor in 1.Conclusion Through anteromedial approach,mini-plate fixation of the ulnar coronoid process fracture provides rigid fixation,which benefits joint stability and bone union,and allows early functional exercise.