[Purpose] The effects of experimental osteoporosis on the trabecular bone structure of the mandible in cynomolgus monkeys were examined by radiological bone morphometric analysis. [Methods] Ovariectomy (OVX) was performed on twelve 10-year-old female cynomolgus monkeys, which were fed a controlled diet for 2 years. Twelve monkeys in a sham control group were fed under the same conditions. Using a microfocus tube and computed radiography, the removed mandibular bone samples were imaged by standardized magnification radiography, and two-dimensional digital imaging data were obtained. The structural parameters, such as skeletal area, perimeter, number, complexity, continuity and anisotropy, were measured using radiological bone morphometric analysis. The bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. The width of the cortical bone was measured using magnified radiographic images. [Results] There were no significant differences between the OVX and the sham control groups in the skeletal structure indicated by the skeletal volume, number, width, perimeter, complexity, continuity, separation and spacing. However, there were significant differences between the two groups in the BMD of the mandibular body, cortical bone width, anisotropy and some parameters of the skeletal continuity. Among these parameters, the difference in the thinning of the cortical bone was most significant. [Conclusions] Using two-dimensional digital radiographic image data, this study suggests that the cortical bone width is more useful than the trabecular bone structure as the morphologic parameter for diagnosis of osteoporosis in the mandibular body.