PURPOSE: The mini-tenotomy is a novel minimally invasive surgical technique that weakens rectus muscles to treat small-angle strabismus. The mini-tenotomy is an alternative to the standard rectus muscle recession that requires hooking the muscle, suturing the muscle, removing the muscle from sclera, and reattaching the muscle to sclera. METHODS: This is a retrospective chart review of outcomes of the mini-tenotomy procedure on 15 consecutive adult patients. A central tenotomy of 3 mm was performed cutting through intact conjunctiva using a blunt Westcott scissors. RESULTS: Preoperatively 6 patients were esotropic, measuring between 2 and 16Delta (mean, 8Delta), and 9 patients had vertical deviations that measured between 2 and 6Delta (mean, 3.5Delta). Final postoperative esodeviations ranged from 1 to 8Delta (mean, 5.8Delta), and hyperdeviations ranged from 0 to 4Delta (mean, 1.3Delta). Final improvement of the deviation was larger for hypertropia, with a mean of 2.3Delta, vs esotropia, with a mean of 1.3Delta. CONCLUSION: The mini-tenotomy is a safe and effective treatment for diplopia caused by a small-angle hypertropia or esotropia. It is a minimally invasive surgery that can be done in office with topical anesthesia. As with any strabismus procedure, more than one surgery may be necessary.