Cimetidine, an H-2 antagonist, is one of the most commonly prescribed drugs and is used in the management of peptic ulcer disease and prevention of stress ulcerations following major trauma or operations. It has been shown that histamine has a stimulatory effect on wound healing which is believed to be mediated through H-2 receptors. We hypothesized that cimetidine would have an inhibitory effect on wound healing. Fifty-two adult rats were divided into two groups: Group A was placed on a standard chow and Group B was given chow supplemented with cimetidine (300 mg/Kg diet), a dose equivalent to that clinically used in man and effective in inhibiting gastric hypersecretion in the rat. Ten days later, all rats underwent a dorsal skin incision under pentobarbital anesthesia and implantation of a polyvinyl alcohol sponge subcutaneously. Animals were maintained on their respective diets. Rats were killed with ether five and ten days postoperatively, the wounds were excised and breaking strength measured. Sponge hydroxyproline content was measured. No significant difference in breaking strength or sponge hydroxyproline content was found between the two groups. We thus conclude that cimetidine has no effect on wound healing in rats when used in doses equivalent to the clinical dose in man.