Objectives: Open tibia fractures pose a clinical and economic burden that is disproportionately borne by low-income countries. A randomized trial conducted by our group showed no difference in infection and nonunion comparing 2 treatments: external fixation (EF) and intramedullary nailing (IMN). Secondary outcomes favored IMN. In the absence of clear clinical superiority, we sought to compare costs between EF and IMN.Design: Secondary cost analysis.Setting: Single institution in Tanzania.Patients/Participants: Adult patients with acute diaphyseal open tibia fractures who participated in a previous randomized controlled trial.Intervention: SIGN IMN versus monoplanar EF.Main Outcome Measurements: Direct costs of initial surgery and hospitalization and subsequent reoperation: implant, instrumentation, medications, disposable supplies, and personnel costs.Indirect costs from lost productivity of patient and caregiver. Societal (total) costs: sum of direct and indirect costs. All costs were reported in 2018 USD.Results: Two hundred eighteen patients were included (110 IMN, 108 EF).