BACKGROUND: This is the fifth study that applied the International Study of Asthma and Allergies in Childhood (ISAAC) methodology in the Southern African Development Community (SADC region). However, it is the first ISAAC study that focused on 6- to 7-year-old children living in South Africa and that also investigated the association between potential risk factors and asthma symptoms. Objective To assess the 12-month prevalence of wheeze and severe wheeze along with their potential risk factors. Setting Within a 60-km radius from the Polokwane city centre, Limpopo Province. METHODS: The survey was conducted during August 2004 and February 2005. Parents/guardians of 6- to 7-year-old children completed the questionnaires in English, Afrikaans or North-Sotho. However, the statistical analyses were restricted to the North-Sotho group (n = 2,437). RESULTS: The 12-month prevalence rates of wheeze and severe wheeze were 11.2% and 5.7%, respectively. The 12-month prevalence rates of eczema symptoms and rhinoconjunctivitis symptoms were 8.0% and 7.3%, respectively. Living in a rural area significantly decreased the likelihood of wheeze by 31%. Exposure to environmental tobacco smoke at home and the presence of eczema symptoms and rhinoconjunctivitis symptoms increased the likelihood of wheeze by 77%, 104% and 226%, respectively. Only the presence of rhinoconjunctivitis symptoms increased the likelihood of severe wheeze by 107%. CONCLUSION: Wheeze appears to be an emerging public health problem in the Polokwane area. Hopefully, detailed analytical intervention studies will further explicate these results in the near future.