A retrospective review of 60 acute fractures of the tibia treated with reamed intramedullary nailing was undertaken to document the spectrum of complications associated with this procedure. Forty-five tibial fractures were followed to radiographic union; follow-up averaged 25 months (range, 10-63 months). Complications were categorized into intraoperative, early postoperative, and late postoperative groups. Intraoperative complications occurred in 6 of the 60 (10%) fractures and included propagation of the tibial fracture into the insertion site of the nail in four cases. In each of two other fractures, at least one of the proximal interlocking screws was documented to have poor bony purchase. These complications did not affect final fracture alignment or clinical result. Early complications included soft-tissue complications, complications of fixation, and neurologic complications. Four patients developed hematomas at the nail insertion site. Eight fractures were stabilized in greater than 5 degrees of varus or valgus. Neurologic deficits directly related to the procedure were documented in 18 patients (30%). The majority were minor sensory neuropraxias of the peroneal nerve. Sixteen (89%) of these nerve palsies were transient, resolving within 3-6 months. Two patients had persistent nerve deficits at 1-year follow-up. In the late complications group, 10 of the 45 (22%) tibial fractures followed to union developed patellar tendinitis. Nonunion developed in two fractures, both of which required additional surgical procedures to obtain fracture union. Two deep infections occurred, both of which resolved after local wound care, fracture union, and nail removal. Overall, 26 of the 45 tibial fractures available for follow-up (58%) developed some complication attributable to the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)