The aim of this study was to evaluate the effect of zoledronic acid (ZA) in the ovariectomized rat on mandibular fracture. Corpus osteotomies were performed on the mandible of ovariectomized rats. Miniplates were placed on these rats, which were randomly divided into 4 groups. After 7 days, groups 3 and 4 were injected with 0.1 mg/kg ZA. Groups 1 and 2 were control groups, so they were injected 0.1 mg/kg saline solution. Animals in groups 1 and 3 were killed at 4 weeks, whereas groups 2 and 4 were killed 8 weeks after operation. The new bone volume of the fracture gap was examined stereologically. Although the difference was not statistically significant compared with the other groups (groups 1 and 3), more bone formation was found in ZA-treated groups (groups 2 and 4) (P < 0.05).