Previous collections in the Departamento del Beni in tropical Bolivia only hinted at high levels of herpetological biodiversity (Fugler 1986, 1988; de la Riva 1990a; Fugler and de la Riva 1990). Fieldwork (totaling 48 days) in July-August 1988 and September 1987 (dry seasons) and November-December 1990 (wet season) has resulted in collection and identification of 401 amphibian and reptilian specimens from the general area of the Beni Biological Station's (EBB) headquarters at El Porvenir. These collections represent 33 amphibian and 17 reptilian species in 29 genera (14 amphibian, 15 reptilian). The inventory of herpetofauna scientifically documented to occur in the Departamento del Beni is considered to have been increased by 6 amphibian and 10 reptilian species. Specimens that could not be definitively identified (reflecting taxonomic uncertainty and/or probably species new to science) include 3 amphibian species (anurans) and 2 reptilian species (snakes). The EBB harbors the richest savanna for anuran species known in South America.