Resumo. Abstract Aim Wetland areas have high environmental complexity and support high biodiversity. Therefore, global efforts are required to preserve these areas. Here, we show the results of three decades of monitoring programs regarding macroinvertebrate species from the upper Paraná River floodplain, which is an important wetland conservation area in the neotropics. Methods We searched the literature from 1990 to 2020 and selected studies that addressed questions related to benthic or macrophyte-associated macroinvertebrates in the study area. Results We retained 92 articles that matched the criteria. We noticed that the number of publications increased after 2009, and most studies were related to lentic environments. Sediment was the most studied substrate, showing the highest taxa record and diversity, followed by aquatic macrophytes. We found records of 517 taxa, from which the families Chironomidae, Cyprididae, and Naididae presented the highest taxonomic richness. The taxa richness observed in our study was lower than the bootstrap richness estimated. Conclusions The lack of signs of curve stabilisation through time for both observed and estimated taxa richness could indicate the macroinvertebrate richness from the upper Paraná River floodplain must be underestimated. In this way, once most of the studies reported results related to long-term ecological research, we argue for the continuity of such studies in floodplains as a powerful tool to assess biodiversity, which can provide useful data for the creation of conservation strategies that enhance the maintenance of biodiversity in such areas.