<p>Chronic inflammation is known to play a critical role in the development of various diseases, such as osteoporosis. The inflammatory potential of a diet can be evaluated using a well-established scale known as the Dietary Inflammatory Index (DII). This study aimed to investigate the relationship between the DII score and the odds of osteoporosis in Iranian women. The study conducted was a case-control study involving 131 postmenopausal healthy women, as well as 131 women with osteoporosis and osteopenia aged 45–65. Osteoporosis was diagnosed through dual-energy X-ray absorptiometry, which measures bone mineral density (BMD) in the femoral neck bone and lumbar spine. To assess the DII score, a validated semi-quantitative food frequency questionnaire was applied. In comparison to the first tertile of DII score, higher and significant odds of osteoporosis/osteopenia were seen in the last tertile (fully adjusted model (body mass index, age, income, education, physical activity, calcium and vitamin D supplements): odds ratio (OR) = 2.43, 95% confidence interval (CI): 1.19–4.95, P_trend = 0.023). Also, individuals in the highest DII tertile had higher odds of abnormalities in femoral neck and lumbar spine BMD (fully adjusted model: OR = 2.85, 95% CI: 1.37–5.89, P_trend = 0.007 and OR = 2.59, 95% CI: 1.29–5.19, P_trend = 0.009, respectively). Based on our findings, it appears that there may be a connection between following pro-inflammatory diets and the odds of osteoporosis in postmenopausal women.</p>