OBJECTIVE Statins have proved to be safe and effective in the secondary prevention of coronary artery disease, but the level of prescription and the reasons for nonadherence to treatment in many coronary diseases treatment centers has not been determined. The purpose of this study was to identify reasons for nonadherence to statin therapy. METHODS We analyzed 207 consecutive patients with coronary artery disease and hypercholesterolemia (total cholesterol > or = 200 mg/dL or LDL-cholesterol > or = 130 mg/dL). Patients' average age was 61.7 +/- 10 year; 111 (53.6 %) male were and 94 (46.6 %) were female. We analyzed the level of prescription and adherence to treatment with statins. RESULTS Statins were prescribed for 139 (67 %) patients, but only 85 (41 %) used the drug. In spite of being indicated, statins were not prescribed in 68 (33 %) patients. Of 54 (26 %) patients, nonadherent to statins, 67 % did not use the drug due to its high cost, 31 % due to the lack of instruction, and only 2 % due to side effects. Total cholesterol (260.3 +/- 42.2 vs 226.4 +/- 51.9; p < 0.0001) and LDL cholesterol (174.6 +/- 38.1 vs 149.6 +/- 36.1; p < 0.0001) were lower in patients on medication. HDL-cholesterol increased from 37.6 +/- 9.6 to 41.5 +/- 12.9 mg/dL (p = 0.02), and triglycerides were not modified in patients using statins. CONCLUSION The prescription of statins in patients with coronary artery disease and dyslipidemia is high; however, its adherence is far from satisfactory, due to the high cost of the medication. Reduction in total cholesterol and LDL cholesterol levels did not reach the targets recommended by the Brazilian Consensus on Dyslipidemia.