Objective To explore the treatment of patellofemoral joint disorders with radiofrequency vaporization under arthroscopy. Methods From June 2004 to June 2007, 86 cases of patellofemoral joint disorder (98 knees) were treated by lateral retinacular release or medial retinacular tighten added, and combined with bipolar radiofrequency chondroplastyunder arthroscopy. There were 30 males (34 knees) and 56 females (64 knees), aging 15-68 years (mean 40 years). The locations were left in 42 cases, right in 32 cases, both sides in 12 cases. The disease course was 3 months to 6 years (mean 30.5 months). In 98 knees, there were 28 knees of static patellar tilt, 10 knees of static patellar subluxation, 45 knees of dynamic patellar tilt and 15 knees of dynamic patellar subluxation. The Lysholm knee score preoperatively was 57.72 ± 8.86. Results The patellofemoral cartilage abnormal ity were classified according to the Outerbridge grade (18 knees of grade I, 36 knees of grade II, 32 knees of grade III and 12 knees of grade IV). The incisions healed by first intention without compl ications such as infection or hemarthrosis. Seventy-five cases (82 knees) were followed up 8-37 months (mean 20.6 months). One month after operation, the patellofemoral joint pain was rel ieved remarkably, the knee joint activity was good and the radiological outcomes was also satisfactory. Six months after operation, the Lysholm knee score was improved significantly in patients of grades I, II and III (P lt; 0.05), while there was no significant change in patients of grade IV (P gt; 0.05). The postoperative score was 69.95 ± 5.42 (P lt; 0.05). Conclusion Radiofrequency vaporization chondroplasty and soft tissue balance under arthroscopy are advantageous in terms of easy operation, less injury, sl ight reaction and have good effect on patellofemoral joint disorders.