Objective To study the effect of microtraumatic treatment of postoperative recurrent bone cysts in juvenile patients. Methods FromDecember 1984 to December 2003, 36 cases of postoperative recurrent bone cysts after focal curettage and bone graft included 19 males and 17 females, aging 9-21 years-with an average of 15 years. The size of bone cyst ranged from 2.5 cm×6.0 cm to 3.5 cm×13.0 cm with an average of 3.0 cm×8.0 cm. The locations were proximal humerus in 18 cases, humeral shaft in 10 and femoral trochanteric region in 8. The focal curette and bonegraft were given once in 23 cases, twice in 10 cases and 3 times in 3 cases. The interval between recurrence and microtraumatic treatment was 5-13 months (6.5 months on average). The posteroanterior and lateral X-ray films were takento determine the location, range and feature of the focus. Under local anesthesia, 2 canulated needles were used; one was used to aspirate the contents of the cyst, the other was used to inject hydrocortisone acetate. The dose was determined according to the range of the focus. The treatment was repeated every 3.54 months until the focus healed. Results All patients were followed up from 3 to 18 years with an average of 5 years. The microtraumatic treatment was repeated 3-11 times with an average of 6 times. Twenty-six cases healed completely, 6 cases healed significantly, and 4 cases healed partially. No local or general complications occurred during the treatment. Conclusion This microtraumatic method for the treatment of postoperative recurrent bone cyst in juvenile patients has following advantages : less pain, easy manipulation, no hospitalization, low cost and definite effect.