Nifedipine, a calcium-channel blocker, is a peripheral vasodilator and has been shown to increase blood flow to skin. The hypothesis that nifedipine would thereby improve skin-flap viability was tested by comparing the extent of necrosis of long pedicle flaps in control and nifedipine-treated rats. Thirty male Sprague-Dawley rats were randomized to receive either 2.5 mg/kg nifedipine in chocolate PO t.i.d. or plain chocolate according to protocols. Serum nifedipine levels were determined by gas chromatography. Dorsal cephalad-based random vascular pedicle flaps (2 X 6 cm) were elevated, sutured to their beds, and photographed for computer-aided surface area determinations. The extent of distal flap necrosis was expressed as a percentage of the total flap area, and differences were studied by one-way analysis of variance. The differences between the mean percentages of necrosis at 1 and 2 weeks for the groups were not statistically significant. We conclude that nifedipine has no effect on the extent of necrosis of the random skin flap in the rat.