This purpose of this study was to evaluate the possible prognostic factors of physeal bar resection in the treatment of partial physeal growth arrest. From January 1979 to October 1993, 23 skeletally immature patients (16 males, 7 females) underwent physeal bar resection and fat graft interposition. The age was ranged from 1 year 8 months to 16 years 9 months (average 8 years 9 months). The follow-up period was ranged from 12 months to 10 years 6 months (average 3 years 4 months). The results of the surgery were categorized into 4 groups on the basis of relative growth ratio (RGR), spontaneous angular correction after physeal bar resection, disappearance of converging growth arrest lines, and the viability & proximal migration of the interposed fat verified by follow-up MRI. The RGR was assessed as a percentage of the contralateral limb segment: change in length of operated limb segment divided by change in length of unoperated limb segment multiplied by 100. The angular correction was calculated as the difference of the degrees of angular deformity between the preoperative and the latest follow-up visit. In the sixteen cases which required concomitant operations (osteotomy, Ilizarov method of for lengthening or deformity correction), their contribution to the angular correction was excluded in the calculation. The etiology of partial physeal arrest consisted of fracture (17), infection (5), and leukemia (1). In 10 of 17 fracture cases in which initial radiographs were available, the Salter-Harris types were assessed. There were type II (2), type III (2) and type IV (6) fractures. Distal femur was the most common site of physeal arrest (13), followed by distal tibia (7), proximal tibia (2), and distal radius (1). There were peripheral (9), combined (6), central (5) and linear (3) types of physeal bar. The nine variables including preoperative limb length discrepancy and degree of angulation, age, onset, etioloty of physeal arrest, Salter-Harris type of epiphyseal injury, site of the arrested physis, type and size.