Objective. To estimate the proportion of patients with familial hypercholesterolaemia (FH) who were identified with hypercholesterolaemia in general practice prior to screening by means of pedigree research and DNA analysis by the National Foundation for the Identification of Familial Hipercholesterolemia (StOEH). Design. Retrospective. Method. General practice files of FH patients, diagnosed through genetic screening by the StOEH in 1992-1997 whose general practitioner's (GP's) practice in Amsterdam, Haarlem or Alkmaar, were studied for cholesterol and FH related information documented in the period prior to the screening. Results. Out of the 121 persons selected 80 agreed to the study; one GP refused to co-operate. There was no difference between respondents and non respondents with regard to age, sex or domicile of the GP. In 48 of 79 (61%) general practice files studied, cholesterol measurements were reported prior to screening; 39 patients (49%) had hypercholesterolaemia and 29 (37%) were being treated with cholesterol lowering drugs. Mean age of the FH patients who had no record of their cholesterol levels was 25.1 years (SD: 17.0) at the time of screening, 22 years younger than the mean age of FH patients who did have cholesterol levels on record prior to screening (47.1 (SD: 18.4); p < 0.0001). Conclusion. Of the FH patients identified through family based genetic screening especially the younger FH patients are newly brought to the attention of their GP.