Diabetes mellitus is a complex disease requiring extensive strategies for effective management. Self-management of diabetes can be expensive and challenging for low-income patients. Current diabetes education and management programs largely target persons with higher levels of formal education and incomes. Kemper, Savage, Niederbaumer, and Anthony (2005) explored differences in knowledge about diabetes among low-income persons who had varying levels of formal education. The present study proposes to extend Kemper et al.’s study to examine the predictive relationship between diabetes self-management knowledge and level of formal education on depressive symptoms in low-income persons with diabetes mellitus. Results may guide nurses in designing effective diabetic education for low income persons who have varying degrees of depression symptoms and varying degrees of diabetes self-management knowledge.