Objectives: We assessed the long-term functional results of surgical treatment of distal intra-articular humeral fractures, together with the factors having influence on the outcome. Methods: Thirty-four patients (25 males, 9 females; mean age 38 years; range 20 to 78 years) who were treated by open reduction and plate osteosynthesis were retrospectively evaluated. All fractures were type C according to the AO classification. Five patients had open fractures. Thirty-three patients had surgery within the first two days after trauma. Posterior (n=19), lateral (n=13), and lateral and medial (n=2) incisions were used. Intra-articular olecranon osteotomy was performed in 11 patients in whom a posterior incision was used. The mean follow-up period was 81.5 months (range 24 to 141 months). Functional evaluation was made according to the criteria described by Jupiter et al. Results: Postoperative complications included infection in four patients, nerve lesion in four patients, nonunion of the olecranon in one patient, and fixation failure in one patient. The mean elbow flexion was 115.1$circ$, and the mean extension loss was 26.3$circ$. Four patients had severe pain and deformities. According to the criteria by Jupiter et al., the results were excellent in six (17.7%), good in 15 (44.1%), fair in nine (26.4%), and poor in four (11.8%) patients. The rate of excellent and good results were higher in closed fractures, in males, in patients at 20 to 40 years of age, in those undergoing posterior incisions and intra-articular olecranon osteotomy, and in patients in whom double-plate osteosynthesis was used. Conclusion: Our results suggest that age, gender, infection, preservation of neural function, successful rigid fixation, an anatomic restoration of the joint surface, and early rehabilitation are effective factors on the functional outcome.