The prevalence of asthma and respiratory symptoms in south-central Durban, one of the most heavily polluted areas of South Africa, has been determined using a cross-sectional survey of 213 households in the communities of Merewent (97% Indians) and Austerville (98% coloreds). The study population consisted of 367 children (less than 17 years old) and 693 adults. About 10% of the children and 12% of adults reported doctor diagnosed asthma. The self-reported prevalence rates for wheezing (3740%) and attacks of shortness of breath with wheeze (16-28%) were much higher than that for doctor diagnosed asthma and common co-occurrence of the three symptoms is found. The prevalence rates for other respiratory symptoms include 33-35% for chronic cough, 31-32% for chronic phlegm, 44-50% for frequent blocked-runny nose, and 16-27% for sinusitis. Factors in the community that were associated with asthma, wheeze and shortness of breath with wheeze among the adult population included cigarette smoking, use of insecticides (coils and pump spray) and home ownership. An association between asthma among children and a number of household risk factors including dampness, carpet, pets or use of pesticides was not apparent in the community. Asthma prevalence was strongly correlated with missing of school by children (odds ratio (OR): 44; 95% confidence interval (CI): 13-141). The study serves to draw attention to a growing but neglected public health problem in urban areas of Africa.