A comparative analysis for parasitoid Hymenoptera visiting the structurally contrasting leaves of Ctenanthe lanceolata (Maranthaceae) and Euterpe edulis (Arecaceae) is presented. A total of 193 hours of observation and 199 sampled plants yielded 569 parasitoid specimens, in 18 families, representing 297 morphospecies. Braconidae, Diapriidae, and Scelionidae were the most abundant and most speciose families, showing sensible differences in the way they use each plant species. The number of specimens and morphospecies per family was significantly different from expected values, suggesting a particular faunistic structure of parasitoid wasps associated with leaves of C. lanceolata and E. edulis. The suitability of the leaves as landing substrate, and their potential in retaining water and hemipteran honeydew droplets, are suggested as main possible reasons for the associations. Absolut wasp diversity, in number of species, is similar for each plant species, but the species are different, and similarity indices pointed to significant faunistic differences between them, even if all singletons are excluded from the analyses. Sex-related preferences for leaves of C. lanceolata or E. edulis were detected to Braconidae, Diapriidae, Scelionidae and Encyrtidae, as a whole or for particular taxa. Data for morphospecies with aggregation tendencies, particularly in Braconidae and Diapriidae, also point to a differential utilization of each leaf type. Evidence ultimately indicate that leaves of C. lanceolata and E. edulis are not randomly visited or utilized by parasitoid wasps, but by functional species assemblages. AI: Y BT: Associations-; Ecology-; Land-zones; Neotropical-region; South-America Hymenoptera-: Associations-, Ctenanthe-lanceolata-and-Euterpe-edulis (plants-) , Non-herbivore-parasitoid-taxa-association-with-leaves, Community-structure, Non-herbivore-parasitoid-taxa-associated-with-plants, Brazil-, Sao-Paulo, Boraceia-Biological-Station, Non-herbivore-parasitoid-taxa-association-with-plants S1: Hymenoptera- (Insecta-) ST: Insecta- none2006