We report the results of nonoperative and operative management of patellar tendinopathy in 42 athletes with Blazina stage 2 (26 patients) or stage 3 (16 patients) patellar tendinopathy, All patients were initially managed nonoperatively with nonsteroidal antiinflammatory drugs, physical therapy, and a progressive rehabilitation program based on isometric exercises, stretching, and eccentric exercises. After 6 months, 33 patients showed symptomatic improvement and were able to resume their sports, In nine patients with Blazina stage 3 tendinopathy, nonoperative measures failed, and surgery was performed. Operative treatment consisted of removal of the degenerated areas of the tendon, multiple longitudinal tenotomies, and drilling of the lower pole of the patella at the site of tendon attachment. Histologic examination of the excised tendon tissue showed areas of necrosis and mucoid degeneration, and alterations of the bone-tendon junction. After a mean follow-up of 4.8 years, clinical results were excellent or good in all patients. In the group treated nonoperatively, results were better in the patients who had stage 2 tendinopathy than in those with stage 3.