Tap water iontophoresis with direct current represents the therapy of choice in palmoplantar hyperhidrosis. Side effects are minor discomfort and skin irritations. Improper use may induce iontophoretic burns at sites of minor skin injuries. The aim of this study was to find ways of minimizing side effects, increasing safety standards and reducing the technical complications of tap water iontophoresis without loss of efficacy. In a blind study, 30 patients with palmar hyperhidrosis were treated with tap water iontophoresis using pulsed direct current of 4.3 kHz or 10.0 kHz. Efficacy and side effects were compared with those of the conventional direct current method as a control. Normal sweat secretion rates of palms were found after an average of ten treatment sessions with the conventional direct current method and after twelve with pulsed direct current of 4.3 or 10 kHz. Treatment with pulsed direct current of 4.3 kHz failed to inhibit palmar hyperhidrosis in two of ten patients. Occasionally, such side effects as discomfort, skin irritation, and mild electric shock occurred when direct current was applied. Using pulsed direct current subjective sensations of discomfort and skin irritation were rare (4.3 kHz) or very rare (10 kHz). Electric shock was completely prevented. Because of the minimal side effects, despite minor loss of efficacy tap water iontophoresis with pulsed direct current can be a valuable alternative treatment for palmar hyperhidrosis.