ABSTRACT. Carioca Lake is located within the limits of the Rio Doce State Park, in the eastern part of the state of Minas Gerais. This park, one of the largest natural reserves of the Atlantic Rain Forest in Brazil, is a hotspot of tropical biodiversity. The purpose of this study was to update existing information on the bathymetry and morphometric features of the lake, using differential GPS (DGPS) technology for data collection, coupled to a digital echo sounder. The bathymetry was based on the acquisition of 1106 points, where the depths as well as the geographic coordinates were obtained. The new study allowed the refinement of existing primary and secondary morphometric data for this lake.