Conventionally, iontophoresis employing direct current (DC) has been used in the treatment of palmoplantar hyperhidrosis, but this is accompanied by side effects such as pain and burns. In the present study, a prototype apparatus using alternating current (AC) was constructed, and iontophoresis with AC was performed in palmoplantar hyperhidrosis patients to determine its effectiveness. The average amount of perspiration of the palmoplantar hyperhidrosis patients was significantly reduced after the third session when iontophoresis treatments were performed once per week. By the eighth treatment, perspiration was reduced to nearly the normal level, and there were no particular side-effects during the treatment period. This treatment therefore appears to be both safe and effective. The treatment effect tended to appear sooner when alternating current iontophoresis was combined with the administration of anticholinergic drugs than when alternating current iontophoresis was used alone. Alternating current iontophoresis is an effective treatment for palmoplantar hyperhidrosis. Guidelines for this treatment for patients with palmoplantar hyperhidrosis will need to be established in the future.