This study describes levels of role strain, diabetes mellitus (DM)–related self-efficacy, depression, and social support in middle-aged Korean women with type 2 DM. Using a cross-sectional correlational survey design, we examined the relationships among these constructs in a purposive sample of 154 Korean women (40–65 years old) residing in Cheon-An, a midsized city in South Korea, who had had a diagnosis of type 2 DM for 6 or more months. Our findings indicated that significant numbers of these women are experiencing significant role strain (52.43 [SD, 8.81]) and are at risk for clinical depression (30%). In bivariate analysis, the level of role strain was negatively associated with diabetes self-efficacy (r = −0.27, P < .01), whereas social support was positively associated with diabetes self-efficacy (r = 0.22, P < .05). A multivariate analysis confirmed that social role strain (β = −.33, P = .00), social support (β = 0.19, P = .05), and age (β = 0.19 P = .03) were statistically significant predictors of DM-related self-efficacy. These findings highlight the importance of social role strain in managing DM and point to the need for appropriate interventions that incorporate the ways to relieve the role strain experienced by this highly vulnerable population.