From January 1987 through December 1990, 28 consecutive distal tibial complicated open fractures in adults treated with primary external fixation and secondary closed Grosse-Kempf interlocking nails were prospectively studied and followed up for at least 1 year. All fractures were type IIIb open fractures and local soft-tissue coverage was performed at 3 to 5 days. The external fixation was maintained for an average of 22 days. The closed interlocking nails were inserted about 2 weeks after Hoffmann pins were removed. The results revealed a union rate of 85.7% (24 of 28) with a period to union of 5.8 +/- 1.4 months. Complications included 14.3% nonunion rate and a 7.2% deep infection rate, which were not difficult to treat. We conclude that secondary closed interlocking nailing is a simple and effective technique in treating distal tibial complicated open fractures.