This paper describes the South Africa component of a World Health Organization multi-site rapid assessment and response project seeking to develop a methodology for studying factors associated with alcohol use-related sexual risk behaviour in diverse cultural settings. This report focuses on the qualitative assessments that were conducted in order to profile alcohol use and sexual behaviour in the communities concerned, ascertain the relationships between alcohol use and sexual behaviour, and develop a conceptual model of the relationships between alcohol use and sexual risk behaviour. The participants consisted of adults aged between 25 and 44 years in a township and city site in Gauteng province. The assessments involved conducting 18 key informant interviews, observations in seven drinking venues, six focus groups and 16 in-depth interviews of 'risky drinkers' and their partners. Most participants felt that there were high levels of alcohol consumption and unprotected sex among some members of their communities, with the latter occurring mainly among casual sexual partners. The findings also pointed to strong links between alcohol consumption and sexual risk behaviour. A conceptual model of the association between alcohol use and risky sexual behaviour is proposed. This study suggests a need for multi-faceted HIV intervention strategies for reducing levels of alcohol abuse in general, and enhancing protective sexual behaviours among alcohol-using populations.