Objective To demonstrate the clinical outcomes and complication rates of the surgical release with a single posterior approach in the treatment of post-traumatic elbow stiffness. Methods A prospective study with patients submitted to surgery between May 2013 and June 2018 in a single center. The access to the elbow was made through the posterior approach. The patients were followed up by an occupational therapy team, and were submitted to a standardized rehabilitation protocol, with static progressive orthoses and dynamic orthoses. The primary outcome was the range of flexion-extension of the elbow after 6 months. Results A total of 26 patients completed the minimum follow-up of 6-months. The mean range of flexion-extension of the elbow at the end of 6 months was of 98.3 ± 22.0°, with an amplitude gain of 40.0 ± 14.0° in relation to the pre-operative period (p < 0.001). The average flexion-extension gain at the end of 6 months was of 51.7% ± 17.1% (p < 0.001). The mean pronosupination at the end of 6 months was of 129.0 ± 42.7° (p < 0.001). Half of the cases had moderate and severe stiffness in the pre-operative period, compared with 7.7% at 6 months post-operatively (p < 0.001). The mean score for the Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) instruments was 74.4 ± 16.8 points and 31.7 ± 21.9 points respectively (p < 0.001 for both). The visual analogue scale (VAS) score presented no statistically significant difference compared to the pre-operative period (p = 0.096). Complications were observed in 6 (23%) patients, and no new surgical procedures were necessary. Conclusions The surgical release of the elbow associated with a rehabilitation protocol is a safe technique, with satisfactory results and low rate of complications.