The purpose of this prospective observational study is to identify whether or not reaming of tibial shaft fractures has benefits over unreamed intramedullary locked nailing. Eighty-four adult patients with recent open and closed tibial shaft fractures were treated with reamed or unreamed intramedullary locked nail fixation. We followed up for 12 months 39 of 43 patients in the unreamed and 38 of 41 patients in the reamed group, respectively. There were no significant differences between the two groups regarding the average time to healing for both clinical (3.2 vs 3.4 months, p = 0.65) and radiological (4.1 vs 4.5 months, p = 0.43) evaluations. The mean duration of surgery was shorter (p = 0.025) for the unreamed group 43 min (SD 18) compared to 55 (SD 27), but the main determinants were the fracture type and the surgeon's experience. We conclude that reamed nailing proved beneficial, but the impact on overall outcome is not superior to unreamed nailing.