OBJECTIVE The aim was to describe the plasma total cholesterol and triglyceride profiles in a random sample of Turkish adults and analyse the effects of certain coronary risk factors on these levels. METHODS This was a cross sectional population based survey. METHODS 59 communities scattered in all seven geographical regions of Turkey were surveyed in the summer of 1990. METHODS A random sample of 3689 men and women 20 years of age and over was studied. RESULTS Plasma total cholesterol, triglycerides, glucose (using Reflotron and with partial validation in reference laboratory), weight, height, and blood pressure were measured, and information on smoking, physical activity, and family income obtained. Hypercholesterolaemia (> or = 6.5 mmol/litre, 250 mg/dl) prevailed in 8.5%, and hypertriglyceridaemia (> 2.25 mmol/litre, 200 mg/dl) in 16.6% among men and women aged 40-59 years of age. Age adjusted total cholesterol values were 4.8 mmol/litre (185 mg/dl) in men and 5 mmol/litre (192 mg/dl) in women. A steep rise appeared in mean cholesterol levels between the ages of 20-29 and 40-49 years, in a ratio greater than the available data from some other populations indicated. Mean total cholesterol values increased substantially in both genders with diminishing grades of physical activity, rising serum triglyceride levels, in urban (opposed to rural) residents, in men with increasing income levels, and in the younger adults with rising body mass index. CONCLUSIONS Turkish adults have comparatively low levels of total cholesterol and medium to moderately high levels of triglycerides. Lifestyle factors affect these levels in Turks as in other populations.