Background Metabolic syndrome is a major health problem in postmenopausal women, along with psychological issues. Hence, this study was conducted to investigate the relationship between metabolic syndrome and mental health properties targeting middle-aged menopausal women, and analyzed the psychological factors affecting the prevalence of metabolic syndrome. Methods The study subjects were 479 postmenopausal women aged 45–64 years, who had taken their routine health screenings from August to October in 2012. The presence of 3 or more of 5 risk factors constitutes diagnosis of metabolic syndrome. Depression, trait anxiety, and stress level were measured by Beck Depression Inventory, State-Trait Inventory, and Brief Encounter Psychological Instrument, respectively. Multiple logistic regression analysis was performed to confirm the relationship between the metabolic syndrome and psychological characteristics. Results The prevalence of metabolic syndrome in postmenopausal women was 16.5%. Metabolic syndrome was significantly related with trait anxiety (odds ratio [OR]=16.53, P =0.007) and depression (OR=0.16, P =0.012), after adjusting for age, marital status, educational level, monthly income, body mass index, eating habits and exercise. Conclusions Trait anxiety and depression were found to be related with the prevalence of metabolic syndrome in postmenopausal women.