Resumo. With the goal of knowing the vespid fauna of the region, weekly samplings were carried out in the Estação Ambiental de Peti, São Gonçalo do Rio Abaixo, Minas Gerais, Brazil. This reserve is inside the Espinhaço Range and is marked by an ecotone formation of Cerrado and Atlantic Forest in its domain. Two Malaise traps were used: one was set in an Atlantic Forest area and the other in Cerrado vegetation. The collecting lasted one year, from April 2002 to April 2003. A total of 553 vespids of 28 species distributed in 11 genera were collected, of which 18 were Polistinae and 10 Eumeninae. The most frequent species were Agelaia myrmecophila (Ducke, 1905), A. multipicta (Haliday, 1836), Polybia flavifrons Smith, 1857 and Mischocyttarus rotundicollis (Cameron, 1912). The abundance was highest in the wet period only for the Polistinae in Atlantic Forest and Eumeninae in Cerrado. Another 18 species were found to occur in the area but were not collected by Malaise traps. The study revealed two species recorded for the first time in the State of Minas Gerais: Pararhaphidoglossa confluenta (Fox, 1899) and Zethus dubius Smith, 1857.