In order to determine the causes of death in camel (Camelus dromedarius) herds managed extensively, 1875 camels, shared in 20 herds, were monitored in the North of Zinder in Niger. The results showed that the mean mortality rate of herd was 4.4%. Except in the first year where the mortality rates were 23 and 34% respectively in the class of age 0-1 year and 1-2 years, the between year variability of the mortality was low. Elsewhere, the probability of death before weaning did not vary between males and females. The mortality rate was 5.9% at six month weaning and 9.9% at 12 months whatever the gender. At reverse, the study of mortality by class of age according to the gender showed that most of the death involved the males less than 2-year old and the female less than one-year old. The higher sensitivity of males between 1 and 2 years could be linked to an early weaning in order to satisfy the milk needs of the family. The determination of the causes of death in camels revealed that young camel diarrhoea was responsible of 80% of the losses. This study confirmed that the health disorders were the main constraints to the camel productivity in extensive system in Niger. (Texte intégral)