In a retrospective multicenter study 28 relapse fractures of the forearm in children were reviewed. The male to female ratio was 23:5. Six children were younger than 6 years, 12 were between 6 and 10 years, and 10 were between 10 and 14 years old. The primary fracture was treated by cast fixation of 3-7 weeks duration. The refracture occurred on a average 14 weeks (4-32 weeks) after the primary fracture by a simple fall (n = 14) or a fall from height (n = 4), or during school (n = 6) or leisure-time (n = 3) sporting activities. In 84% of the patients partial consolidation, i.e. incomplete healing of one cortex of one or both forearm bones, preceded the refracture. In the majority of patients this was observed after a green stick fracture due to permanent angulation. Six patients were operated upon for irreducibility of the relapse fracture; the others were treated by conservative means. In two patients a second refracture occurred. Fifteen patients were available for a 2 year result. Definitive angulation of more than 10 degrees caused a clinically relevant limitation of pro-supination in five of six patients. To prevent relapse fractures of the forearm in children, complete circular consolidation of the original fracture has to be guaranteed. It remains unclear whether this is best achieved by special plaster techniques or by converting a greenstick fracture into a complete, unstable fracture.