BACKGROUND: The treatment of open tibial shaft fractures remains controversial. Important considerations in surgical management include surgical timing, fixation technique and soft tissue coverage. This study was performed to evaluate the results of acute surgical debridement, unreamed nailing and soft tissue reconstruction in the treatment of severe open tibial shaft fractures. PATIENTS AND METHODS: During a 10-year period between January 1993 and July 2002, 927 tibial shaft fractures were treated with interlocking intramedullary nails. Among them, there were 19 consecutive patients with Gustilo type IIIB to IIIC open tibial shaft fractures with extensive soft tissue injury needing a muscle flap coverage and being suitable for intramedullary nailing. All 19 patients were called for a late follow-up which was conducted with a physical examination and a radiographic and functional outcome assessment. The radiographs were reviewed to determine the fracture healing time and the final alignment. RESULTS: All 19 open fractures with severe soft tissue injury healed without any infection complications. The fractures united in a mean of 8 months. Nine patients had delayed fracture healing (union time over 24 weeks). One of these patients needed exchange nailing, one patient autogenous bone grafting and dynamisation on the nail and seven patients needed dynamisation of the nail before the final fracture healing. In all patients, the alignment was well maintained. However, seven patients had shortening of the tibia by 1-2 cm and two of them also external rotation of 10 degrees . The functional outcome was good in 18/19 patients. INTERPRETATION: Acute surgical debridement, unreamed interlocking intramedullary nailing and soft tissue reconstruction with a muscle flap appear to be a safe and effective method of treatment for Gustilo type IIIB open tibial shaft fractures.