Lipid-lowering medication can significantly reduce the risk for cardiac events in patients with dyslipidemia. Despite well-publicized guidelines and the availability of potentially effective therapies, many patients do not achieve their lipid goals and remain at high risk for cardiac events because of poor adherence. To assess adherence to statin therapy based on an analysis of pharmacy records, the records of 562 patients were screened. A washout rule, designed to ensure that only new medication starts were analyzed, resulted in the inclusion of 140 records in this study. Dates of prescription fillings, drug name and strength, quantity dispensed, and the number of days supplied were recorded. Length of therapy, persistence, medication possession ratio (MPR), and median gap between prescriptions were calculated. Overall persistence declined from 56% at 9 months to 35% at 12 months. Persistence at the study end point was 34% for men, 18% for women, 19% for patients younger than 65 years, and 41% for patients aged 65 years and older. The median number of gap days between prescription refills was 6.83 for all patients and was approximately 7 days longer for women than for men. The number of gap days differed only slightly for patients younger than 65 years compared with patients aged 65 years or older (6.44 vs 7.41, respectively). MPRs ranged from 0.64 to 0.56, with no substantive between-group differences. Among the statins used most often in this study, persistence was highest with atorvastatin (36%) compared with simvastatin (26%) and pravastatin (5%). Adherence to statin therapy can result in significant improvement. In patients with dyslipidemia, personal interventions by healthcare providers can improve compliance with potentially effective therapy.