The cryoprotective effect of sucrose has been investigated using 3 different vascular smooth muscle preparations, namely canine saphenous veins and arteries and porcine circumflex coronary arteries following storage in liquid nitrogen (at –196°C). Contractile responses to noradrenaline, 5-HT, prostaglandin F₂ and KCl and relaxant responses to substance P and 5-HT were determined on fresh tissues and after cryostorage in fetal calf serum (FCS) containing either 1.8 M dimethyl sulfoxide (DMSO), or 0.1 M sucrose or both agents combined. The data demonstrate that the addition of sucrose to the DMSO-containing cryomedium promotes the preservation of both contractile and relaxant activity of cryostored blood vessels, though sucrose alone did not confer any noticeable protection.