Background: We aimed to report the clinical and electrophysiological results of patients who weretreated with an endoscopically assisted in situ release technique for cubital tunnel syndrome and toshow safety and efŞcacy of this procedure.Materials and methods: Twenty nine patients were included into the study. 13 patients (44.8%) werefemale, 16 patients (55.2%) were male. The mean age was 44.4 years (range; 22e66 years). Mean followup period was 16.0 months (range; 7e42 months). We used Dellon classiŞcation for preoperative staging,and modiŞed Bishop rating system for the evaluation of postoperative clinical results. Dynamometric andelectromyographic measurements were obtained preoperatively and atŞnal control.Results: Preoperative Dellon's classiŞcation revealed 3 patients grade 1, 14 grade 2, and 12 grade 3.ModiŞed Bishop score was very good for 21 patients (72.4%), good for 4 patients (13.8%), fair for 3 patient(10.3%), and poor for 1 patient (3.4%). AtŞnal control; the mean proportion of grip power and pinchstrength of the affected hand to the contralateral normal hand was improved, and also nerve conductionvelocity were improved in all patients. As complication, hematoma formation developed in two cases.Conclusion: Our study showed that endoscopically assisted decompression technique without using anyspecial instruments can be performed successfully with a low complication rate. It is a safe and effectivemethod in the treatment of cubital tunnel syndrome.Level of evidence: Level IV, Therapeutic study© 2017 Turkish Association of Orthopaedics and Traumatology. Publishing services by Elsevier B.V. This isan open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).