Femoral neck fractures in children are very rare and account for about 1% of all paediatric fractures. The aim of this retrospective study was to analyse the clinical and radiographic outcome in paediatric femoral neck fracture and to review the role of early decompression of the hip in the final outcome. The study was performed at the Department of Paediatric Orthopaedics and Traumatology, University Children's Hospital in Belgrade, Serbia from January 1996 to January 2010. The study included 28 patients, 12 female and 16 male, aged 4-14 years. Patients who were aged over 14 years or who had pathological femoral neck fractures or metabolic disturbances were excluded from the study. The type of neck fracture was determined according to the Delbet and Colonna classification. The patients were treated using different surgical procedures: closed reduction and cast immobilisation, closed reduction and percutaneous fixation with Kirschner wires (K-wires), closed reduction and fixation with cannulated screws and open reduction with Wagner plate stabilisation. The final outcome was evaluated using the clinical outcome (based on the Howorth-Ferguson scale), radiographic outcome and occurrence of complications. The median age of patients included in the study was 10.75 years and the average follow up was 9 years. According to the Delbet classification, there was one patient with type I, eight patients with type II, 16 patients with type III and three patients with type IV femoral neck fracture. Based on the Colonna classification, there were 23 displaced and five non-displaced femoral neck fractures. Decompression of the hip was performed in 21 patients. Avascular necrosis (AVN) developed as the main complication in 11 patients. The final outcome was excellent in 14 patients, good in four patients and poor in 14 patients. Our study unequivocally confirms the positive effect of urgent treatment on the incidence of AVN as well as on the outcome. We have established a 12-hour interval after injury as an optimal time limit for commencing treatment. Unambiguously positive effects of hip decompression on the incidence of AVN were also noted. We found similar efficiency for open and needle hip decompression.