We have revised all the specimens of Araneidae from the Colombian Amazon Region in the Arachnological Collection of the Instituto de Ciencias Naturales at the Universidad Nacional de Colombia (ICN), in addition to the specimens collected between 2000 and 2004 by the authors in the lower Caquetá and Apaporis rivers (Amazonas and Vaupés, Colombia). A total of 77 new records for Araneidae in the Colombian Amazon are reported; 26 of these species are new records for the country and the region in addition to 15 more species known for Colombia but newly recorded in the region, the distribution of the remaining 36 species is expanded within the region. The genera Encyosaccus Simon 1865 (E. sexmaculatus Simon 1895), Hingstepeira Levi 1995 (H. folisecens Hingston 1932) and Micrepeira Schenkel 1953 (M. fowleri Levi 1995 and M. tubulofasciens Hingston 1932) are recorded for the first time in Colombia. From this revision, it is evident the great amount of new information available in museum collections. Due to the strategic geographic position of Colombia, species inventories in different localities of the Colombian Amazon Region are important to fill distributional gaps of many species in South America. This work contributes to the knowledge of geographic distribution patterns of orb-weaving species in Colombia and in the entire Amazon Region.