The authors report the results of a retrospective study conducted on 30 cases of fracture of the tibia and femur submitted to external fixation and subsequently to intramedullary osteosynthesis, treated between 1991 and 1999. Intramedullary osteosynthesis was used in 24 cases (5 in the femur and 19 in the tibia) as treatment subsequent to external fixation for nonunion or delays in consolidation. Sequential nailing was used as planned treatment in the remaining 6 cases. In 83.3% of cases the fracture was open (Gustilo Anderson type I (30%), type II (20%), type III (33.3%). The mean duration of external fixation was 13.24 weeks, and infection occurred in 4 cases (13.33%) during that time. Removal of the external fixator and intramedullary osteosynthesis were carried out during the same surgical session in 40% of the cases, while nailing was preceded by a period in plaster lasting an average of 4 weeks in the remaining 60% of cases. All of the cases achieved consolidation an average of 31 weeks after trauma, and 14.7 weeks after intramedullary synthesis. We observed the occurrence of infection in 3 cases (10%), but this did not keep consolidation from occurring.