An experimental study was designed using Hartley guinea pigs to evaluate wound contraction on animals receiving systemic isotretinoin at a dose of 10 mg/kg. Half the animals received isotretinoin for 4 weeks before the surgery and for 2 weeks after the surgical procedure. A square of skin and panniculus carnosus measuring 200 mm2 was excised from the back of each animal, and the amount of wound contraction was determined by a computer program from the drawings on celluloid overlays done weekly. The animals on systemic isotretinoin had a significant delay in wound contraction when compared to control animals (p less than 0.001). When the medication was discontinued, all the animals had complete wound healing within a week.