Injury potential may have a regulatory role in the wound healing process, and exogenous electrical stimulation (ES) may mimic natural endogenous bioelectric current that can improve wound healing. Until now, the influence of externally applied ES on injury potential has not been demonstrated during the healing of acute wounds. Thirty-nine male guinea pigs were randomly divided into a control group (sham treatment) and two experimental groups: anodal and cathodal direct current (DC). A 2.5 cm-long full-thickness skin incision was made on each animal's dorsal region. Differential skin surface potential was measured before and immediately after the injury and also through day 21 of the healing period; wound surface area (WSA) was also measured throughout the 21-day healing period. Immediately after injury, wound potential significantly increased in all three groups, reaching a maximum on day 1 for the control and cathodal groups and day 3 for the anodal group (p < 0.05), then decreasing through the healing period. Wound potential returned to preinjury levels by the end of the healing period in the anodal group only. By days 19 and 21, wound potential had decreased more for the anodal group than the control group (p < 0.05). By day 15 for the anodal group and day 17 for the cathodal group, WSA had decreased more compared with the control group (p < 0.05). Anodal microamperage DC ES is appropriate for improving the healing of acute skin wounds because it causes both the wound surface to close and the wound potential to return to preinjury levels faster.