All pompilids use spiders to provide food for their larvae, and these hunting wasps can be responsible for a significant impact on the populations of their prey. Data on spider species captured, characteristics of the nests, fecundity and seasonal variation in reproductive frequency, however, are not available for most pompilid species. Here we describe the nesting behavior of Auplopus argutus based on 108 nests from an area of Atlantic Forest in southeastern Brazil. The wasps deposited each spider in a clay vessel, constructed within the bamboo cylinders used as traps. In each trap we found from 1 to 19 vessels, totalizing 508 provisioned cells. From these, 84 contained spiders in good conditions of conservation, allowing identification. The females of A. argutus provisioned their nests with 21 spider species, belonging to eight families: Anyphaenidae, Corinnidae, Ctenidae, Miturgidae, Salticidae, Senoculidae, Sparassidae and Zoridae. Almost all the spiders collected in the nests had their legs amputated and were equivalent or greater in size than the mean body size of the wasps.