PURPOSE This study was to identify the mental health and self-care activities according to perceived stress level in type 2 diabetic patients with metabolic syndrome. METHODS The descriptive survey design was conducted using a convenient sample. One hundred and fifty-two diabetic participants with metabolic syndrome were recruited in a university hospital. The data were analyzed using descriptive statistics, Students' t-test, and ANOVA with SPSS/WIN 12.0. RESULTS The high, moderate, and low stress groups according to perceived stress score consisted of 30.9%, 38.2%, and 30.9%, respectively. Differences of mental health and total self-care activities among the three groups were statistically significant. Depression (F=46.73, p<.001), trait anger (F=5.75, p<.01), and anger expression-in (F=4.60, p<.01) of participants in the high stress group were higher than other groups, whereas the total of self-care activities (F=2.85, p<.05) and exercise (F=3.49, p<.05) were lower than other groups. CONCLUSION This study concluded that type 2 diabetic patients with metabolic syndrome with a high stress level were low in self-care activities along with elevated depression and anger.