This prospective study investigated medium-term outcomes for 51 children treated from 1997 to 2001 for displaced diaphyseal forearm fractures with elastic stable intramedullary nailing. Forty-three patients included achieved excellent/good functional results at an average follow-up of 38 months. Four patients required open fracture-manipulation at surgery. Complications included eight cases of soft-tissue irritation at nail-insertion site (three required shortening procedures), two temporary radial nerve branch injuries, four minimal rotational mobility deficits, one 10 degrees elbow extension deficit after splinting, and five small keloid scars. All patients were pain-free, without limitations in activities for daily life or sport/play activities by 12 months after hardware removal. Elastic stable intramedullary nailing is appropriate therapy for these injuries.