Objective. To describe lipid-lowering treatment in a primary care setting and how well target levels are reached. Furthermore, the aim is to describe long-term adherence to treatment. Design. Population-based cross-sectional study with follow-up. Setting. A total of 139 general practices from three of five Danish regions, taking part in the ADDITION study from 2001 to 2006. Subjects. The study population comprises 1468 patients who started lipid-lowering drugs and were followed for a minimum of one year after starting treatment. Median time of follow-up after starting drug therapy was 936 days (range: 3662068). Results. Of 1468 patients starting treatment, a total of 781 (53%) reached the treatment goal of total cholesterol <5.0 and low-density lipoprotein <3 mmol/l within one year after drug therapy start. The percentage increased throughout the study period from 27% of patients initiating treatment in 2001 to 66% of patients initiating treatment in 2005. Age over 50, repeated cholesterol measurements within three months after treatment start, larger initial dose, and calendar year of treatment start were associated with reaching the goal within the first year, and most recent total cholesterol measurement before start of treatment >7 mmol/L was associated with not reaching the goal in the first year. Among patients followed for a minimum of three years after drug therapy started (n = 536), adherence was 77%, 72%, 75% in the first, second, and third year respectively. Conclusion. Initial doses and the percentage reaching their goal increased substantially throughout the study period. Adherence to lipid-lowering treatment is relatively high in a primary care setting. However, current practice shows room for impr.