The benefits of the carbon dioxide (CO2) laser in the treatment of verruca resistant to other forms of treatment have been studied. Twenty-five patients with warts unsuccessfully treated from one to five times previously were treated with the laser, followed for a minimum of 6 months, and evaluated. Eight of these patients (32%) gained a total permanent cure. An additional five treatments resulted in a subtotal (over 75%) cure but some warts remained. Thus, 13 of 25 patients (52%) experienced complete or partially successful treatment. The CO2 laser is a valuable modality in the treatment of recalcitrant warts but cannot be expected to cure all such warts.