Technical Abstract: The Gossypium hirsutum gene pool from Mexico is one of the primary sources for improvement of most of the Acala and Upland cotton growing in the world today. Mexico is also the center of diversity of 11 of the 13 known diploid arborecent Gossypium species of the Western Hemisphere D genome. In 2002 and 2003, the current status of these important genetic resources was surveyed and germplasm was collected in the western states of Mexico. Information was needed to verify current status and circumscriptions for the species of the Gossypium genus endemic to Mexico. Sixty years after the first in-depth studies of Gossypium in Mexico, increasing population, modernization and urbanization have severely impacted the survival of G. hirsutum landraces in the country. Representatives of cotton land races appear to survive only as curiosities in garden plots or dooryards, and as feral plants. Populations of seven known species, G. aridum, G. barbadense, G. gossypioides, G. hirsutum, G. laxum, G. lobatum, and G. schwendimanii, and one undescribed taxon of the wild diploid Gossypium species were located during the survey. In situ conservation of some of these species is threatened. Samples of the collected germplasm were deposited in the Cotton Collection of the U.S. National Plant Germplasm System where they will be available to scientists worldwide for research, breeding, and education. Additionally, a Gossypium species nursery is being established by the Mexican government for the preservation and as a working legacy of this resource.