The Herbarium from the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” (BA Herbarium) was the first official herbarium in Argentina. It was initiated in 1853 and holds about 150,000 herbarium specimens at present, most of them collected all over Argentina, but also obtained by exchange with other national and international botanical institutions. About 100,000 correspond to vascular plants, and 800 represent nomenclatural type specimens. Cactaceae type material deposited at BA is presented. This article includes a list of the 60 type specimens alphabetically arranged; scientific names with taxon authors, original publication data and type category are transcribed from the original labels. Current accepted scientific names are also included. Under observations, ecological information or additional comments written by the author of the description are given. Under notes some consideration of our own, most regarding to the current synonymy, are given. These type specimens are kept in special metal cabinets, separated from the rest of the herbarium material and documented with a copy of the original diagnosis or publication. As part of the Digitalization of Biological Collections Project carried out by the museum, the complete information of each specimen was digitalized and is available online through the web site of the Sistema Nacional de Datos Biológicos (SNDB) and the Global Biodiversity Information Facility (GBIF).