Background Patellar tendinopathy is a common source of pain in athletes, especially those involved in sports with a high incidence of jumping and cutting. Changes in training programs and exercises based on eccentric quadriceps contractions often relieve patients' symptoms. For athletes unresponsive to this treatment, some authors suggest open and arthroscopic procedures débriding either the tendon alone, or the tendon and bone. Questions/purposes We asked whether an arthroscopically assisted approach to débride not only the tendon, bone, but also the peritenon could relieve pain and allow athletes to return to their former activities. Patients and Methods We retrospectively reviewed 23 patients with a history of at least 6 months of painful patellar tendinopathy unresponsive to nonoperative treatment treated with an arthroscopic technique that débrided the tendon, inferior pole of the patella, and peritenon: 22 males and one female. Mean age was 29 years. Patients were evaluated using the anterior knee pain score of Kujala et al. The minimum followup was 12 months (mean, 58 months; range, 12-121 months). Results Twelve patients scored 100, one 99, one 98, five 97, two 94, one 90, and one 64. The Kujala et al. mean score was 96 (range, 64