A combination of diarrhoea and malnutrition frequently occurs in HIV seropositive children and constitutes a bad prognosis factor. The impact of dehydration induced by diarrhoea in these children has not as yet been assessed and constitutes the aim of this study. This retrospective analysis was conducted on 121 malnourished children monitored in 1994 at an infant home in Cöte d'lvoire. 46.2% of the children were HIV seropositive and their mortality rate was significantly higher than that observed among seronegative children (42.8% vs. 15.3%; p < 0.01). Among the various pathologies observed in these children, diarrhoea and oral candidosis were discriminating factors in seropositive children. Besides, the findings confirmed the effect of dehydration on the mortality of malnourished children as a whole. Studies allowing a better understanding of factors involved in diarrhoea or dehydration among HIV seropositive malnourished children appears to be essential to improve the management of these children.