In line with the strategic recommendations of the Global Plan of Action for the Conservation and Sustainable Utilisation of Plant Genetic Resources for Food and Agriculture approved at the Fourth International Technical Conference on Plant Genetic Resources (ITCPGR), Leipzig, Germany, June, 1996 and of the Global Plan of Action on Food Security approved at the World Food Summit on Food Security (WFS), Rome, November, 1996, the Andean Countries of Latin America (LAC) face the need to strengthen the use of modem plant biotechnology for the conservation and sustainable agricultural use of genetic resources of under-utilized crops. Advanced biotechnologies as cell and tissue culture, molecular genome analysis, plant genetic transformation, molecular plant disease diagnosis and germplasm cryo-conservation can be successfully used to cope genetic erosion, to reinforce ex-situ collections and in in-situ conservation, to upgrade the supply of improved and healthy seed and planting materials to farmers and to integrate a new approach into the development programmes for food production and food security in mountain lands. Over the centuries, more than seventy crops have been domesticated by the Andes inhabitants. Presently, on twenty eight crop species, selected under the basis of adaptation to high altitude, agronomic use and yield, nutritional value and market potential, there are relative developments in term of agronomic cultural management and scarce genetic conservation activities. The Technical Co-operation Network on Plant Biotechnology (REDBIO) for the Latin American Countries (LAC), sponsored by FAO since, 1990 have detected for this subregion technical constrains in terms of scarcity of human resources, limitation in technology development and use, infrastructure and lack of information/data banks on plant biotechnology. Eighty six plant biotechnology laboratories from the Andean Countries of LAC (Colombia, Peru, Ecuador, Bolivia, Venezuela are members of REDBIO. On several of these institutions there are research and transfer of technology projects, including plant biotechnology, on Andean under-utilized food crops as arracacha (Arracacia xanthorrhiza), achira (Canna edulis), yacon (Polymnia sonchifolia), mashua (Tropaeolum tuberosum), oca (Oxalis tuberosa), ulluco (Ullucus tuberosus), quinoa (Chenopodium quinoa), amaranto o kiwicha (Amaranthus caudatus), popping beans -"nunas" (Phaseolus vulgaris), tarwi (Lupinus mutabilis), goldenberry-"capuli" (Physalis peruviana), cherimoya (Annona cherimola) and passion-fruit (Passiflora sp.). The paper summarizes the main parameters and characteristics of 13 selected crops including the state of the art of plant biotechnology in the Andean countries and main applications and discusses perspectives and future impact of plant biotechnology for the conservation and development of food crops.