Faunal inventories provide quantitative and qualitative data for different sites and are relevant sources of information for identifying areas of high species richness and endemism. Biological collections are important in this context for increasing the precision of species identification. The objectives of this study were to update the list of bat species of Ilha Grande by analyzing specimens in zoological collections as well as records obtained in areas where no such studies had been undertaken before; to compare five different studies conducted on Ilha Grande using mist net sampling; and to compare the results of studies on Ilha Grande with sampling results from other areas in Rio de Janeiro state. The occurrence of 36 bat species was confirmed for Ilha Grande. Five studies on Ilha Grande formerly conducted by the authors were compared with 34 fauna inventories in Rio de Janeiro state. The studies on Ilha Grande had distinct objectives and sampling techniques applied to different locations in the same area. Ilha Grande is one of the regions in Rio de Janeiro state with more bat records both in terms of abundance and number of species, as well as one of the areas of highest bat capture effort.