The study examined the impact of dietary advice on cholesterol reduction, to see whether diet was more effective when preceded by a cholesterol estimation. A total of 635 healthy individuals aged between 40 and 60 years attended a general practice cardiovascular risk screening in 1990. All subjects had their blood pressure, body mass index and smoking history recorded, and 50% were randomised to cholesterol measurement. Two years later, all individuals were invited to participate in a follow-up screening and 356 individuals took part (158 men, 198 women). All the above estimations were undertaken in 100% of attendees. The mean total cholesterol levels and weight declined in the subjects who were given dietary advice and had their cholesterol measured, while the mean cholesterol level increased slightly in subjects who did not receive dietary advice but had their cholesterol measured. The was a significant increase in diastolic blood pressure in all patients. The figures for reported smokers decreased from 22.4% to 19.4% in men and 19.4% to 8.4% in women. The results suggest that dietary advice can achieve a sustained reduction in cholesterol levels, but may require the stimulus of a prior cholesterol estimation.