This is a prospective analysis on 30 physically active individuals with a mean age of 48.9 years (35 to 64) with chronic insertional tendinopathy of the tendo Achillis. Using a transverse incision, the tendon was debrided and an osteotomy of the posterosuperior corner of the calcaneus was performed in all patients. At a minimum post-operative follow-up of three years, the Victorian Institute of Sports Assessment scale – Achilles tendon scores were significantly improved compared to the baseline status. In two patients a superficial infection of the wound developed which resolved on antibiotics. There were no other wound complications, no nerve related complications, and no secondary avulsions of the tendo Achillis. In all, 26 patients had returned to their pre-injury level of activity and the remaining four modified their sporting activity. At the last appointment, the mean pain threshold and the mean post-operative tenderness were also significantly improved from the baseline (p < 0.001). In patients with insertional tendo Achillis a transverse incision allows a wide exposure and adequate debridement of the tendo Achillis insertion, less soft-tissue injury from aggressive retraction and a safe osteotomy of the posterosuperior corner of the calcaneum.