The authors have studied the geographical distribution of 33 freshwater prawn species found in Brazil and surrounding areas, as part of a research project which views the development of a national technology for the freshwater prawn culture. The fauna comprises litoral species found in lowlands along the coast, in areas limited at the south by the 15ºC isotherm for the average air temperature of the coldest month, and continental species, which can be separated in tropical, subtropical and temperature ones, whose occurrence areas were delimited by the 20ºC and 15ºC average air temperature of the coldest month.