An increase in the surviving area of skin flaps was achieved by local injections of alpha-adrenergic and beta-adrenergic blocking agents. Dorsal skin flaps of albino rats were injected postoperatively at their bases with Regitine (Ciba-Geigy, Switzerland), propranolol and a combination of these two drugs, two or three times daily for 6 days. All the pharmacologically treated animals showed a significantly better flap survival rate than did the control group (P less than 0.001). More frequent injections gave increasing flap survival areas. However, a combination of the above-mentioned drugs did not improve the results when compared with propranolol administered alone, and was less effective than Regitine administered alone.