The pathogenesis of keloid formation is poorly understood. The fibroblasts in keloid patients continue to multiply even after initial wound repair and are characterized by a persistent dermal fibroproliferative reaction and excessive extracellular matrix production. Most studies concentrate on the type of collagen produced within keloids and the cytokines that dominate the disease. There have been considerably fewer studies in the expression of messenger RNA level in key cell cycle genes of the keloid fibroblast. The aim of this study was to measure the messenger RNA expression of the key regulators of cell cycle, cell cycle cyclins, and cyclin-dependent kinases, and their inhibitors.