A screening model based in general practice for the detection of subjects at risk of premature cardiovascular disease is described. Opportunistic screening is performed by a trained nurse who also gives initial advice on management. Immediate feedback to patients is possible since a rapid dry chemistry technique is used to measure blood cholesterol concentrations. The collation and analysis of data are achieved using a microcomputer. A central deidentified database is incorporated to allow epidemiological studies and intervention strategy evaluations to be made. Nineteen health centres have evaluated the model, and 40,000 subjects have been screened: 10% had diastolic blood pressures of over 95 mm Hg and 15% had a blood cholesterol concentration over 7 mmol/l (270 mg/100 ml) and 2% over 9 mmol/l (347 mg/100 ml). The initial data suggest that the model is acceptable to both health centre personnel and the general public and that the offer of screening is taken up by all elements of the target population.