Many surgical procedures have been described to weaken the inferior oblique muscle overaction. This study is designed to evaluate the results of inferior oblique muscle tenotomy that were performed in cases with primary inferior oblique muscle overaction. Inferior oblique muscle tenotomy was performed to 46 eyes of 28 patients with primary inferior oblique muscle overaction. Unilateral tenotomy was performed to 10 patients (35.7%) and bilateral to 18 patients (64.3%). While there were full correction in 40 (87.0%) eyes, inferior oblique overaction as grade 1 in 3 eyes (6.5%) and grade 2 in 3 eyes (6.5%) was observed in the postoperative period. Adherence syndrom or inferior oblique muscle underaction were not observed in any of the cases. As a result; inferior oblique muscle tenotomy seems to be quite effective and reliable in patients with primary inferior oblique muscle overaction.