Significant differences in the prevalence of coronary heart disease (CHD) exist with respect to gender, age and ethnicity. The disease has been reported to be higher in Indian populations that have emigrated from the Indian subcontinent. The aim of this study was to examine differences in major cardiovascular risk factors and clinical outcome in South African Asian Indians of different age groups and gender, who presented with acute coronary syndromes (ACS). The study cohort consisted of 2 290 consecutive patients, admitted between 1996 and 2002, who were divided into three age subgroups: young ( </= 45 years; 20%), middle age (> 45 to </= 65 years; 59%), and old age (> 65 years; 21%). All three age groups were predominantly male, but this was more evident in the younger (88%) and middle age groups (71%), and became less striking as the proportion of females increased with age. Smoking was more common in young men compared with young women (p < 0.01). Diabetes mellitus (21%) and hypertension (18%) were seen less frequently in young patients but this was confined to men only. Total cholesterol was elevated in 65 to 70% of all patients while high-density lipoprotein (HDL) levels were significantly lower in men compared with women for all age subsets. Hospital mortality was extremely low in young (1%) and middle-aged patients (2%), but was expectedly higher in older patients (8%; p < 0.0001). A family history of CHD was the most common familial vascular disease seen. Young patients were more often subjected to diagnostic and therapeutic interventions. They had more aggressive disease, with 48% of those subjected to angiographic studies having triple vessel disease (TVD), and 14% undergoing coronary artery bypass grafting (CABG). Triple vessel disease was also detected most commonly in middle-aged (64%) and old patients (75%). In conclusion, significant differences in risk factor status were found in South African Indians between genders and for different age groups. Also, young Indians in this study differed markedly from other young population groups with CHD, in that they frequently had premature atherosclerosis with diffuse and aggressive disease.