OBJECTIVE Presentation of technical experience and the clinical and functional results of intramedullary fixation of forearm shaft fractures. METHODS Between January 1994 and December 2009, a total of 96 patients with 144 radial and/or ulnar fractures (ulna, 33; radius,15; both, 48) were treated by nailing (True/Flex®). According to the AO classification there were 22-A, 22-B and 22-C type fractures in 39 (41%), 44 (46%) and 13 (13%).cases, respectively. Of these, 82 (85%) were closed (types: 0, 48; I, 33; II, 1) and 14 (15%) were open (types: I, 13; II, 1; III, 0) fractures. Seventy-eight patients (81%) were followed up and their functional outcomes were evaluated according to the criteria of Anderson et al. The average interval between the operation and final follow-up was 28 months (15 to 96 months) RESULTS The average time to surgery was 2.2 days (0 to 25 days). Early complications were recorded in 4% of the patients (1x bursitis olecrani; 1x end cup replacement; 1x bending of nails) and late complications in 15% (5x non-union; 2x delay union; 4x bursitis olecrani; 1x ruptured tendon). Bone healing was achieved in 95% of the cases and took on average 16 weeks (7 to 34 weeks). No infection, refracture or synostosis occurred. Primary loss of reduction was recorded in four cases due to distraction in one, bent nails in two and a wrong size of the implant in one; secondary loss of reduction was found in three cases, with two cases of radius shortening and one 10°malrotation. No primary malrotation was recorded, but secondary loss of alignment was seen in the distal part of the radius and the proximal part of the ulna. Functional results according to the Anderson criteria were excellent and good in 87% of the cases. CONCLUSIONS Intramedullary mailing provides good stability to mid- and distal-third shaft fractures of the ulna and mid- and proximalthird shaft fractures of the radius, particularly in AO type A and type B fractures. The technical aspects of the method are analysed in detail in this paper. CONCLUSIONS True/Flex® intramedullary nailing, because of its minimally invasive approach and close reduction, allows us to minimise the risk of wound and neurovascular complications, especially in proximal shaft fractures of the radius.