When two cholera epidemics broke out in Djibouti, respectively in 1993 and 1994, Bioforce was obliged to intervene. The first time, three goals were pursued: setting up a rehydration centre in a tent, organizing epidemiological surveillance and training local personnel in treatment and diagnosis techniques. The next year, the epidemic followed serious flooding. The epidemiological analysis showed that cholera had become endemic in the poor neighbourhoods of the town and that epidemic break-outs were favoured by contaminated surface water and disturbances in the distribution of drinking water. The epidemic of 1997, likewise following flooding, only confirmed this point of view.