Method for processing uncertain information originating from a plurality of heterogeneous sources, adapted to be applied in an automatic decision support system based on uncertain information, comprising steps of: - obtaining of a hierarchical structured model (G) which defines entities and relationships between said entities, said entities being representative of the uncertain information to be processed, and - obtaining of a plurality of observations (Obs i ), each observation having an associated level of certainty of observation, each observation being composed of information values corresponding to at least a portion of the entities of said hierarchical structured model (G), the method being characterised in that it further comprises the following steps, which are carried out by a processor of a programmable device: - determination of a structured representation of each observation according to the hierarchical structured model (G), - fusion of the determined structured representations in order to obtain a fused structured representation, - obtaining of a plurality of fused sets (E i ), each fused set comprising elements, each element corresponding to an entity of the hierarchical structured model (G) and being either equal to said entity or equal to an observed information value associated with said entity according to at least one of said observations (Obs i ), such an observation being called an observation contributing to said fused set (E i ), and for each fused set (E i ), calculation of an associated overall level of certainty taking into account the level of certainty of observation associated with each observation contributing to said fused set, the calculation comprising: ∘ the association of a belief weight with each observation contributing to said fused set, equal to the level of certainty associated with said observation, and o a multiplicative-additive combination of the respective belief weights associated with each observation contributing to said fused set. - obtaining of a hierarchical structured model (G) which defines entities and relationships between said entities, said entities being representative of the uncertain information to be processed, and - obtaining of a plurality of observations (Obs i ), each observation having an associated level of certainty of observation, each observation being composed of information values corresponding to at least a portion of the entities of said hierarchical structured model (G), - determination of a structured representation of each observation according to the hierarchical structured model (G), - fusion of the determined structured representations in order to obtain a fused structured representation, - obtaining of a plurality of fused sets (E i ), each fused set comprising elements, each element corresponding to an entity of the hierarchical structured model (G) and being either equal to said entity or equal to an observed information value associated with said entity according to at least one of said observations (Obs i ), such an observation being called an observation contributing to said fused set (E i ), and for each fused set (E i ), calculation of an associated overall level of certainty taking into account the level of certainty of observation associated with each observation contributing to said fused set, the calculation comprising: ∘ the association of a belief weight with each observation contributing to said fused set, equal to the level of certainty associated with said observation, and o a multiplicative-additive combination of the respective belief weights associated with each observation contributing to said fused set. ∘ the association of a belief weight with each observation contributing to said fused set, equal to the level of certainty associated with said observation, and o a multiplicative-additive combination of the respective belief weights associated with each observation contributing to said fused set. <EOS>