Background. The aim of our study was to assess the effectiveness of treatment in adolescent patients with chondrolysis and avascular necrosis of the hip, based on our own clinical material. Material and methods. The study included 14 patients treated in the Pediatric Orthopedics and Traumatology Department at County Hospital no. 2 in Rzeszow, Poland, from August 1999 to July 2005. The mean age of the patients was 13.4 years (range 11-19). 10 patients were treated surgically, while 4 were treated conservatively. The effectiveness of the treatment was assessed using the McKay classification scheme after the follow-up period (mean 47 months, range 8-62). Results. Clinical improvement was observed in 10 patients (71.4%). Excellent results were found in 4 patients (28.6%), good results in 2 patients (14,.%), satisfactory results in 4 patients (28.6%), and poor results were 4 patients (28.6%). The post-surgical shortening of the affected limb averaged 2 cm (range 1-3). Conclusions. The data we obtained show that the best outcomes in the treatment of adolescent patients with chondrolysis and avascular necrosis of the hip is assured by early detection of the disease.