This study presents a checklist of large and medium size mammals at Estação Ecológica Mata do Cedro, municipality of Carmópolis de Minas, Minas Gerais, Brazil. Between June 2008 and February 2009 we applied sand plots, active search and camera traps for the species inventory. Sand plots were inspected for five consecutive days every two months. We registered 21 species of mammals: 14 on sand plots, 13 by the active search (direct and indirect evidence) and four in the camera traps. Most species were common to other studies in the Atlantic forest, and not listed as threatened on the Brazilian red list, but two (Puma concolor and Myrmecophaga tridactyla) are considered vulnerable to extinction in Brazil. The reserve holds high species richness in relation to other studies and may have an important role in the conservation of the Atlantic forest mammals.