In Soweto, infant morbidity and mortality from gastro-enteritis have markedly declined. Nevertheless, there were 1514 admissions to the Baragwanath Infant Gastro-enteritis Unit in a 12-month period (1985/6). Oral rehydration therapy (ORT) could be implemented with advantage not only as a life-saving strategy but for self-help management of milder diarrhoea. Surveys conducted in Soweto and at Baragwanath showed that 84 (22%) of 382 mothers/minders of children knew formulas for acceptable salt-and-sugar oral hydration solutions (OHS), although 203 (53%) claimed to have knowledge of ORT. One hundred and ten interviewees (29%) were aware of the desirability of giving extra fluid to a child with diarrhoea. A need exists for health educators to explain and ensure understanding of the basic concept of adequate fluid replacement that is fundamental to ORT. This important message may have been overshadowed by emphasis on choice of containers and different formulas with consequent confusion.