Between January 1980 and December 1989, 133 consecutive patients were treated for a fracture of the shaft of one or both forearm bones (134 forearms in total). All fractures were stabilized with AO/ASIF 3.5 mm stainless-steel dynamic compression plates. The 1 year follow-up rate was 99 per cent; the long-term follow-up rate was 92 per cent (the mean long-term follow-up was 10.2 years (range, 2.7-15.2)) so there were 96 men and 35 women, with an average age of 37.5 years (range, 16-63). Twenty-two per cent of the forearms had open fractures, 26 per cent of patients had sustained multiple injuries and 19 per cent had a head injury. One hundred and twenty-seven of 132 forearms (96.2 per cent) underwent problem-free consolidation before 6 months. Two delayed unions and two non-unions required reoperation. There was one superficial infection in a patient with a closed fracture. Plates were removed from 70 patients (53 per cent) at a mean of 33.1 months (range, 8-122) after the first operation. In this group, there were three refractures (4.3 per cent) occurring at a mean of 8.7 months (range, 0-14) after plate removal. This study confirms the safety and efficacy of plate osteosynthesis in forearm shaft fractures: a high union rate and low complication rate can be anticipated. The data presented form the most reliable information on this subject currently available with the longest and highest rate of follow up of a sufficient number of patients using a single implant system in a single institution.