This study examined the volume of oral rehydration solutions given to children during diarrhea and the length of time the solutions are administered. It also attempted to test the importance of individual and contextual factors--especially mothers' knowledge--in explaining the administration of oral rehydration solutions. Data about the treatment of an episode of child diarrhea within the last three months were collected from large samples of mothers in seven sites in Africa, Asia, and Latin America. The results showed that oral rehydration solutions were given in smaller volumes and for shorter periods of time than recommended. The majority of children received at least a glass (200-250 ml) of solution on the first day, but few received more than that. Daily administration of packet-based solutions or of sugar-salt solutions (promoted in two of the countries) during diarrhea was generally quite low, ranging from 16 to 60% of cases given an oral rehydration solution. However, in four out of six sites, at least half of the children with diarrhea for more than one day were given an oral rehydration solution for more than one day. The majority of children were given some form of other fluids (e.g. more water, special teas, or continued breastfeeding), but their value in preventing dehydration was not clear because the volume of other fluids given could not be assessed. Few of the hypothesized predictors of administration explained the variation in volume or duration of ORS/SSS administration within any specific country or across sites. The research points to the need for more information on the decision process used by mothers when treating their children's diarrhea and on outside factors influencing this process.