A 10-year-old boy presented with a Salter-Harris II distal radius fracture that was irreducible by closed methods. An open reduction was performed in the operating room where a sleeve of periosteum was found interposed between the fracture fragments. Successful reduction was performed without difficulty after the periosteum was removed from the fracture. Soft-tissue interposition must be kept in mind when having difficulty performing closed reductions of pediatric distal radius physeal fractures to avoid excessive reduction attempts.