AbstractDidelphis albiventrisis the opossum with the largest geographic distribution in Brazil and has a wide spectrum of helminth parasites. This study aimed to describe the species composition and analyse the structure of helminth communities ofD.albiventrisin two extremes of the Atlantic Forest in Brazil. The influence of host sex, body mass, age, helminth species richness and locality on the abundance and prevalence of the most prevalent helminth species was investigated. Ninety-five per cent of the animals were infected with at least one species. Nine helminth species were found: the nematodesAspidodera raillieti,Cruzia tentaculata,Trichuris didelphisandTrichuris minutain the large intestine;Turgida turgidain the stomach;Travassostrongylus orloffiandViannaia hamata; and the trematodesBrachylaima advenaandRhopalias coronatusin the small intestine. Three helminth morphospecies were also recovered: the nematodesHoineffiasp. andViannaiasp. and a cestode in the small intestine.Cruzia tentaculataandV.hamatawere the species with the highest mean abundances and intensities, while the most prevalent species wereA.raillieti,C.tentaculata,T.turgidaandV.hamata, forming the central nucleus of the helminth component community. The analysis of the helminth metacommunity structure indicated a Gleasonian pattern for the total set of infracommunities, corroborating the beta diversity indices, which indicated more species replacement than loss between localities and infracommunities, although at a low level. The results indicated a stronger influence of host attributes than geographical distance on the community structure.