Objective: The authors report their experience in the treatment of the diaphyseal tibial fractures, using the unilateral radiolucent External Fixator (EF) XCaliber., Design: A total of 100 patients (average age 35 years, range 16-76) with 103 displaced diaphyseal tibial fractures were treated with the XCaliber. There were 59 type A fractures, 35 type B, and 9 type C (according to the AO classification) and 35 were open fractures., Main Outcome Measurements: During the last assessment, patients were evaluated for level of pain, ability to perform weight-bearing activities, and number of residual deformities., Results: The average follow-up time was 24 months, 3 patients (4 fractures) were excluded for final assessment and 1 patient moved abroad. Of the remaining 98 fractures, 83 (84.7%) healed with a single operation in a mean 21 weeks (SD 3.97; 12-38 weeks), 10 fractures had a delayed union and 5 fractures proceeded to a non-union. There were 13 complications. Among them, a loss of reduction was observed in 3 cases due to overload of the EF, in 3 cases, deep pin track infections were observed and 2 fractures healed with more than 1 cm of shortening., Conclusions: The results are encouraging, since both complex and open fractures were included in this study. The XCaliber was shown to be a valid unilateral external fixator, combining the advantage of radiolucency during application and radioscopic follow-up with a stable and flexible fracture fixation. This represents the first report in the literature specifically examining treatment of tibial diaphyseal fractures with a radiolucent external fixator.