To examine the influence of ultraviolet radiation, a potent inducer of interleukin-1 and other growth factors, on the rate of epidermal migration, we used a porcine model of wound healing. Wounds were treated in one of the following treatment groups: (1) two minimal erythema doses of ultraviolet radiation once daily for 2 days before wounding, (2) two minimal erythema doses of ultraviolet radiation once daily for 2 days before wounding followed with continuous treatment until all wounds were 100% epithelized, (3) or no ultraviolet radiation treatment until healing was complete. Using a macroscopic salt-split technique, we examined epidermal specimens macroscopically for epithelialization. Treatment both before and after ultraviolet radiation significantly enhanced epithelialization when compared with non-ultraviolet radiation-treated control wounds. These experiments show that ultraviolet radiation treatment can augment the rate of healing of partial-thickness wounds.