OBJECTIVE: Use of acetyl salicylic acid (ASA) for primary prevention (PP) and secondary prevention (SP) of cardiovascular disease (CVD) in adult diabetic patients is highly recommend. This study was conducted in order to determine the use of ASA and to assess the achievement of therapeutic targets in diabetic patients. METHODS: This is a retrospective and observational study. Sample consisted of patients > 18 years with diabetes mellitus followed in four primary care centers. Measurements included demographics, use of ASA and/or anticoagulant drugs, co-morbidities, clinical parameters and proportion of patient at therapeutic target (TT). Descriptive statistics, chi-square test and logistic regression model were used for significance. RESULTS: A total of 4140 diabetic patients were analyzed, 79.1% (95% confidence interval: 77.7%-80.5%) in PP and 20.9% (18.2%-23.7%) in SP. Mean age was 64.1 (13.8) years, and 49.3% of patient were men (PP: 46.3; SP: 60.7; p=0.000). ASA were prescribed on a routine basis in 29.2% (27.8%-30.6%); 20.8% (19.4%-22.2%) in PP and 60.8% (57.6%-64.0%) in SP. Proportion of patient at TT was 48.0% for hypertensives and 59.8% for hypercholesterolemics, being these the most frequent antecedents observed in SP. Older patients [OR=1.01 (1.00-1.02); p=0.011], number of cardiovascular-risk factors [OR=1.14 (CI: 1.03-1.27); p=0.013], LDL-c TT [OR=1.42 (1.06-1.88); p=0.017], and a poor metabolic control of glycated hemoglobin [OR= 1.51 (1.22-1.89); p=0.000] were covariates associated to the use of ASS in PP. CONCLUSIONS: Treatment with ASA is underused for PP in patients with diabetes mellitus in Primary Care. Achievement of TT should be improved.