Osteosarcopenic obesity syndrome is a condition including osteopenia, sarcopenia and obesity. A pro-inflammatory dietary pattern has been reported to be associated with obesity and osteoporosis. However, studies on the association of dietary inflammatory index with osteosarcopenic obesity syndrome in the Korean population are lacking. The aim of this study was to analyze the relationship between dietary inflammatory index and osteosarcopenic obesity syndrome among Korean postmenopausal women. We analyzed the 2009–2011 Korea National Health and Nutrition Examination Survey, consisting of 1,344 postmenopausal women aged 50 years or older. Body composition was evaluated by dual-energy X-ray absorptiometry. Dietary inflammatory index was estimated after analyzing 36 nutrients and 9 foods using a 24-h dietary recall data. The association between dietary inflammatory index levels and the body composition was analyzed by logistic regression models with dietary inflammatory index fit as a dichotomous variable. The dietary inflammatory index was −0.96 ± 0.22 in the normal group, 0.12 ± 0.16 in the osteopenic obesity group, 0.00 ± 0.18 in the osteosarcopenia group, 0.12 ± 0.33 in the sarcopenic obesity group, and −0.02 ± 0.14 in the osteosarcopenic obesity group ( p <0.001). After adjusting for potential covariates, women with higher dietary inflammatory index scores were more likely to have risk of osteopenic obesity (OR = 2.757, 95% CI: 1.398–5.438, p <0.01) and that of osteosarcopenic obesity (OR = 2.186, 95% CI: 1.182–4.044, p <0.05). The results indicate that pro-inflammatory diet was associate with increased odds of the osteosarcopenic obesity in postmenopausal Korean women. Therefore, studies are needed to identify the effects of anti-inflammatory diets, which can reduce the degree of inflammation through dietary intake.