We performed arthroscopic procedures on 97 knees in 91 patients younger than 16 years of age. Sixty arthroscopic procedures in 58 patients were for sports-related injuries or symptoms. The most common diagnosis was maltracking of the patella. In 78 cases, an operative procedure was performed at the time of diagnostic arthroscopy. No complications were experienced. The accuracy of diagnosis for suspected meniscal tears was poor. Further pathologies, especially meniscal tears, were commonly associated with anterior cruciate ligament tears. Arthroscopy of the knee in children is safe, has a high diagnostic accuracy, and, in a significant proportion of patients, it can have not only a diagnostic role but allows the management of a wide variety of intra-articular conditions.