BACKGROUND: General Practitioners (GPs) play a central role in controlling an important risk factor for cardiovascular diseases, i.e. cholesterol levels in serum. In the past few decades different studies have been published on the effect of treating hyperlipidemia with statins. Guidelines for treatment have been adopted. We investigated the consequences on the practice of GPs screening cholesterol levels and on the timing of starting statin prescription. METHODS: For this descriptive study, data from the Intego database were used, composed with data from the electronic medical records (EMR) of 47 general practices in Flanders. GPs had not received special instructions for testing specific patients. For each patient the mean cholesterol level per year was calculated. A patient belonged to the group with lipid-lowering drugs if there was at least one prescription of the drug in a year in his EMR. Mixed model linear regression models were used to quantify the effect of covariates on total cholesterol values. RESULTS: In the period 1994-2003 total cholesterol was tested in 47,254 out of 139,148 different patients. Twelve percent of those tested took lipid-lowering medication. The proportion of patients with at least one cholesterol test a year, increased over a period of ten years in all age groups, but primarily for those over the age of 65.The mean cholesterol level decreased in the treated as well as in the non-treated group. Of the patients with a cardiovascular antecedent who were on lipid-lowering drugs in 2003, 56% had a cholesterol level </= 199 mg/dl, 31% between 200-239 and 13% over 240 mg/dl. CONCLUSION: The indications for testing and treating cholesterol levels broadened considerably in the period examined. In 2003 cholesterol was tested in many more patients and patients were already treated at lower cholesterol values than in previous years. Comparisons of cholesterol levels over different years should therefore be interpreted with caution as they are a reflection of changes in medical care, and not necessarily of efficacy of treatment.