There is a trend towards increase in the incidence of coronary heart disease among Indian population. Also, little information is available on the population distribution of serum lipid components and risk factors for coronary heart disease in Kerala, a state fast turning urban. To study the serum lipid profile and the prevalence of other risk factors for coronary heart disease in the residents of an urban housing settlement in Thiruvananthapuram, fasting blood sample was collected from 206 (64%) residents above the age of 19 years and analysed for plasma glucose and various fractions of serum lipids. A detailed questionnaire on the clinical profile and history of the subjects, and measured weights and heights was also administered. Mean serum total cholesterol was 223.7 +/- 45.3 mg/dL; 223.7 +/- 44.9 mg/dL among males and 223.7 +/- 45.8 mg/dL among females. Mean high-density lipoprotein cholesterol was consistently higher in females in all age groups, while mean low-density lipoprotein cholesterol was higher in males till the age group 40-49 after which the pattern was reversed. Mean total cholesterol in the age range 35-64, after age standardisation, was 229.4 mg/dL. Mean serum total cholesterol was higher in this sample when compared to US population, as well as north and west Indian populations. Thirty-two percent subjects were in the highest risk category with serum cholesterol exceeding 239 mg/dL, while in the US population this fraction constituted only 18 percent. Other risk factors such as high blood pressure, obesity, diabetes, sedentary lifestyle and smoking also had a high prevalence in this population. In this settlement of urban residents in Thiruvananthapuram, serum total cholesterol and low-density lipoprotein cholesterol are high. The causes are likely to be dietary. Combined with the high prevalence of other risk factors such as obesity, hypertension, smoking, diabetes and lack of exercise, this situation demands a preventive programme.