The ultrasonic surgical aspirator (USA) offers unique surgical options in the treatment of vulvar intraepithelial diseases. Clinical observations have shown results that equal those achieved with the use of the carbon dioxide laser with regard to patient satisfaction and incidence of recurrent disease. The purpose of this study was to compare the USA to the carbon dioxide laser in the laboratory with respect to ease of use, adequacy of epithelial removal, amount of tissue damage, and timing of wound healing. The backs of ten Hartley guinea pigs were marked with eight 1-cm2 patches placed 2 cm apart. Each instrument was used to ablate or resect the area within four patches on each animal's back to the level of the mid-dermis (0.5-1.0 mm). At time intervals from 0 hr to 28 days, the eight 1-cm patches were removed and evaluated histologically. The USA was easier to control and maintain within the 1-cm2 patch than the laser was. On histologic evaluation, the USA demonstrated less adjacent epithelial damage. The peak inflammatory response, depth of collagen denaturation, reepithelialization, and healing at 28 days were similar in both groups. The study indicates that the ultrasonic surgical aspirator is effective in epithelial removal and allows rapid wound healing with minimal scarring.