Objectives: (1) To identify the major sources of nutrition information, and the perceived credibility thereof, among urban black South African women; and (2) to determine the level of knowledge regarding nutrition, particularly regarding the topic of obesity. Design: A cross-sectional descriptive study that was both qualitative (focus groups) and quantitative (individual questionnaires). Three hundred and ninety-four black women aged 17-49 years were conveniently sampled from the Western Cape and Gauteng provinces in South Africa. Methods: Four focus groups were held with 39 women to identify common themes relating to nutrition knowledge. Based on these data, a questionnaire instrument was developed and administered to 394 women by trained fieldworkers. Results: The most frequently encountered source of nutrition information was the media, particularly the radio and TV (73.4% and 72.1% of subjects, respectively, obtained information from this source in the past year), followed by family/friends (64.6%). Despite only 48.5% of subjects having received nutrition information from a health professional, this was the most highly credible information source. Factors being most influential in choice of foods were taste, preferences of the rest of the family, and price. A lack of knowledge on certain aspects of nutrition was identified, as well as misconceptions regarding diet and obesity. Conclusion: To improve nutrition knowledge and the effectiveness of nutrition education activities in South Africa, it is recommended that health and nutrition educators become more actively involved with the training of health professionals, particularly those engaged in delivery of services at primary care level, and in turn encourage health professionals to engage more with media sources. Nutrition messages delivered from health professionals via the media will enable public exposure to nutrition information which is not only easily accessible but also perceived to be highly credible.