Open tibial shaft fractures were analyzed retrospectively to determine the effect of treatment timing on infection and nonunion rates. The cases of 77 patients with 81 open tibial shaft fractures were reviewed. Patients were treated with initial wound cleansing and splinting in the emergency department and then formally with operative irrigation and débridement and stabilization, which included intramedullary (IM) nailing, external fixation, open reduction and internal fixation, or splinting. All tibial shaft components ultimately were treated with IM nailing. Mean time to operative treatment was 12.97 hours (SD, 10.8 hours). There were 7 infections (8.6%) and 3 nonunions (3.7%). Time was found not to be a significant factor in predicting either infection or nonunion. Increased severity of fracture was a significant factor in predicting infection rate. The infection rate for fractures treated first with external fixation and then with IM nailing was significantly higher than that for fractures treated with IM nailing alone. In addition, a relation was found between patients who received multiple débridements and development of infection. These results show that infection and nonunion rates were not adversely affected by longer time to operative treatment (up to 48 hours) when adequate trauma department open fracture care and early initiation of antibiotics were coupled with standardized and thorough débridement in the operative theater.