The nutritional benefit of milk consumption during diarrhoea must be balanced against its potential to produce increased severity or duration of illness. Continued breastfeeding during diarrhoea results in decreased stool output and is generally recommended. However, continued feeding of non-human milk may cause increased faecal excretion, prolonged diarrhoeal duration, and a greater number of treatment failures among young patients with relatively severe diarrhoea. Although most children can safely continue receiving milk during acute diarrhoea, the possibility of serious complications dictates that they be carefully observed. Acceptable alternatives to exclusive non-human milk feeding during diarrhoea include milk-free formulas, milk-cereal mixtures, and possibly fermented milks. This paper reviews the results of published clinical trials of milk feeding and discusses their implications for the appropriate dietary management of childhood diarrhoea.