This study aimed to investigate the correlation between panoramic radiographic indices and osteoporosis, and determine whether digital panoramic radiographs could be used as a screening tool for the diagnosis of osteoporosis in Thai postmenopausal women. This was a cross-sectional study of sixty Thai postmenopausal women with and without osteoporosis. The participants were divided into three groups based on a diagnosis of their bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA): normal, osteopenia, and osteoporosis equally in each group. Panoramic radiographic indices measured are mental index (MI) and mandibular cortical index (MCI). The Pearson’s correlation test was performed to analyze the correlation among MI, MCI, and BMD t-score. To determine the ability of the indices, to classify disease and investigate the cut-off value of MI for diagnosis of osteoporosis, the receiver operating characteristic analysis was performed. The P value was set at 0.05. From this study, it was found that MCI were significant differences between the three groups (p<0.001). There were correlations between panoramic radiographic indices and BMD in the regions of the hip bone and the lumbar spine. MI was positively correlated with BMDs: lumbar spine: r=0.566, femoral neck: r= 0.554, and total hip: r= 0.524 (p<0.001). MCI was negatively correlated with BMDs: lumbar spine: r= -0.514, femoral neck: r= -0.507, total hip: r=-0.513 (p<0.001). The cut-off value of MI for the reduced skeletal BMD groups (both osteopenia and osteoporosis groups) was 3.9 mm and for the diagnosis of osteoporosis was 3.8 mm. The results of this study suggest that MI and MCI can be used as a screening tool for the diagnosis of osteoporosis in Thai postmenopausal women.