The anthropological study of the approach of target diseases in the Expanded Programme of Immunization (EPI) in Bouna, a semi-rural district of Northeast Côte d'Ivoire, shows that the population is well-informed about each disease named in this programme as well as for modern vaccination but its objectives remain completely unknown. Populations' reluctances towards vaccination can be explained by several "organizational" causes: overestimated cost of vaccination records, incoherence in the follow-up of vaccination and disruption in the cold chain. These organizational problems are induced by the programme itself and appear more determining than those corresponding to cultural opposition to explain the poor results of the EPI in Bouna. Therefore improvement of these results is linked to the quality of the health cares which can be provided.