We conducted a retrospective analysis of 94 children with fractures of the distal third of the radius, with or without ulnar fractures, treated by primary closed reduction and plaster. The overall failure rate of 29% was due mainly to irreducibility, inability to maintain reduction and eventual limitation of forearm rotation. Age, sex and severity of angulation were not significant, but the direction of angulation and the degree of translation at either the radial or the ulnar fracture sites were significant risk factors. Translation of the radius was the single most reliable predictor of outcome (83% correct). The risk of failure in fractures with translation of the radius of more than half the diameter of the bone was 60%, compared with 8% for fractures with less translation.