The recent application of DNA marker technology offers a valuable tool for revealing the genetic basis of both simple and complex traits in crop plants. In agriculture, it brings extraordinary promise for streamlining many plant breeding efforts, particularly for introgression of valuable genes from exotic germplasm and breeding for traits affected by many quantitative trait loci (QTLs). DNA markers in cotton create unprecedented opportunities for improving competitiveness of U.S. cotton (Gossypium hirsutum L. and G. barbadense L.) production, by accelerating breeding progress and targeting genetic changes. We are currently identifying DNA markers that are linked to fiber strength and other important traits (Glandless, Photoperiod sensitivity, immature fiber, and Ligon lintless-2) in cotton.