The purpose of this study was to investigate the effect of electrical stimulation on ischemia-induced tissue injury in skin flaps. Bipedicle skin flaps measuring 4 X 20 cm were created bilaterally on the flanks of 12 Yorkshire pigs. The ischemic central portions of the flaps were treated with 35 mA of electrical current at a frequency of 128 Hz for 30 minutes twice daily during the initial nine days following skin-flap elevation. The treatment schedule consisted of negative-electrode stimulation during the first three days, positive-electrode stimulation during the second three days, and negative-electrode stimulation during the seventh to ninth days. Five control pigs underwent either no treatment (n = 3) or sham treatment (n = 2). The mean area of the skin flaps exhibiting necrosis was 28.0% in the control animals and 13.2% in the stimulated animals. These areas were significantly different (p less than .001). The results indicate that pulsed electrical stimulation can improve the survival of skin flaps.