Contraction and epithelization are two phenomena of "wound healing" retarded by corticosteroids. It is unclear how these agents affect collagen synthesis and wound remodeling. The methods used by several authors to conclude that steroids inhibit collagen synthesis are questioned. Therefore, collagen synthesis was measured in cultured steroid-treated chick embryo calvaria, 5 day open wounds in treated rats, and intralesionally injected human keloids. Collagen synthesis was suppressed only by long-term administration of massive systemic doses of a sustained release form of methylprednisolone (Depo-Medrol). Large, intermittent doses of corticosteroids (triamcinolone and Solu-Medrol) did not alter collagen synthesis. Because human keloids become softer and smaller following intralesional administration of triamcinolone without lowering the normally high rate of collagen synthesis, we hypothesize that corticosteroids enhance collagen degradation.