This study aimed to assess the knowledge about diabetes, the attitude for self-care and associated factors through a cross-sectional study, the baseline of a randomized clinical trial with elderly diabetic in primary health care in Recife, Northeastern Brazil. We used the Diabetes Knowledge Scale (DKN-A) and Diabetes Attitudes Questionnaire . Of the 202 elderly, 77.7% had insufficient knowledge of the disease, especially for ketonuria, food replacement and were unaware of the causes and care of hypoglycemia. As for attitude, 85.6% had a negative psychological adjustment for diabetes. The logistic regression model showed that living alone was a protective factor (OR = 0.24; 95% CI 0.09-0.65; OR = 0.22; 95% CI 0.07 to 0.71), and low education, a risk factor (OR = 7.78; OR = 13.05; for the insufficient knowledge and the negative attitude for self-care, respectively. The findings reinforce the need for interdisciplinary educational actions that include socioeconomic, psycho-emotional and educational aspects in diabetes management to maintain elderly autonomy and functionality.