PURPOSE: To report the results of unreamed nailing using a nail with the largest possible diameter for the management of the open tibial shaft fractures. MATERIALS AND METHODS: Nineteen patients with open tibial shaft fractures underwent unreamed nailing with the largest possible diameter according to the isthmic diameter measured on preoperative radiography. There were 1 Grade I, 6 Grade II, 9 Grade IIIa, 3 Grade IIIb open fractures. There were 4 type A, 12 type B, 3 type C fractures according to the OTA classification. Fractures were classified as The nail was introduced after gentle passage of a 7 to 8 millimeter-hand reamer. RESULTS: Union was obtained in all cases. However 9 (47%) fractures required an additional procedures before union. In 6 cases, dynamization was done. Two of them were required exchange nailing for nonunion, 1 of two gained bony union through additional bone graft. Three of the others had gained union through exchange nailing, bone graft, bone transport respectively. There were one rotational malunion, one superfical and one deep infection. Interlocking screw breakage developed only in one patient. CONCLUSION: Our data indicate that unreamed nailing in the management of open tibial fractures is safe and reliable method. Using a tight fitting nail with the largest possible diameter is a safe and effective way to avoid the problems of screw breakage.