Objective: The main purpose of the present study was to assess the radiographic, histological, and mechanical effects of gabapentin on fracture healing in a rat model of femur fracture. Materials and methods: A standard transverse fracture of the mid-diaphysis was created. A total of 60 female Wistar-Albino rats with the mean age of 13.5 ± 1.2 weeks were used for this experimental trial. The rats were randomized into four groups with 15 animals included in each group. Group A and B were the control groups whereas C and D were the treatment groups. Drugs were delivered by oral gavage twice a day with the daily dosage calculated according to body surface area conversion to the human equivalent dosing regimen of 1200 mg/day. Radiographic, histological, and biomechanical evaluation was performed. Results: We could not detect any statistically significant difference between the control and gabapentin treatment groups according to the comparative assessment of radiographic scores on the 15th and 30th days. Although no significant differences were found between the groups on the 15th day, histological scores were better in the control group on the 30th day. According to the results of biomechanical testing, the fractured femurs resected from the control group exhibited significantly more strength on the 30th day. Conclusions: According to the data we acquired during the present study, administration of gabapentin negatively affects the fracture healing process especially in the aspects of histological progression as well as the biomechanical strength of the callus in a rat model.