Type 2 diabetes mellitus (T2DM) is a chronic disease affecting more than ten percent of the U.S. adults. Approximately 50 percent of people with diabetes fail to achieve glycemic targets of A1C levels below seven percent. Poor glycemic control disproportionately affects minority populations such as Korean Americans (KAs). Successful diabetes self-management requires a comprehensive approach that takes into account depression, sleep, and acculturation to achieve good glycemic control. Therefore, the purposes of this study were to: 1) describe the levels of glycemic control, depressive symptoms, sleep quality and duration, and acculturation; 2) examine an association of depressive symptoms with glycemic control; 3) identify mediational roles of sleep quality and sleep duration of less than 6 hours between depressive symptoms and glycemic control; and 4) explore a moderation role of acculturation between depressive symptoms and glycemic control in KAs with T2DM. This is a cross-sectional, descriptive correlational study. A total of 119 first generation KAs with T2DM were recruited from Korean communities in Arizona. A1C levels, the Center for Epidemiological Studies Depression Scale, the Pittsburgh Sleep Quality Index, the Suinn-Lew Asian Self-Identity Acculturation scale, the International Physical Activity Questionnaire, and the Berlin Questionnaire were measured. Descriptive statistics, multiple regression analyses, path analyses, and the Sobel tests were conducted for data analyses of this study. Poor glycemic control (A1C ≥ 7 %), high depressive symptoms (CES-D ≥ 16), poor sleep quality (PSQI > 5), and short sleep duration (< 6 hours) were prevalent among KAs with T2DM. The mean score of acculturation (2.18) indicated low acculturation to Western culture. Depressive symptoms were revealed as a significant independent predictor of glycemic control. Physical activity was negatively associated with glycemic control, while cultural identity was positively related to glycemic control. Sleep quality and sleep duration of less than 6 hours did not mediate the relationship between depressive symptoms and glycemic control. Acculturation did not moderate the association between depressive symptoms and glycemic control. Diabetes self-management interventions of a comprehensive approach that considers depressive symptoms, sleep problems, and cultural differences in minority populations with T2DM are needed.