The Q-switched ruby laser at 694 nm, a wavelength well absorbed by melanin relative to other optically absorbing structures in skin, causes highly selective destruction of pigment-laden cells. In addition, the 20- to 40-ns pulse duration produced by this laser approximates the thermal relaxation time for the melanosomes, thereby confining the energy to the target. The Q-switched ruby laser was used to treat 47 patients (11 males and 36 females) with nevus of Ota during the period December 1991 to 1994. The involved facial area ranged from 3 x 3 cm2 to 20 x 20 cm2. The energy fluence used varied from 8 to 10 J/cm2, and the number of treatments ranged from 1 to 8 (mean 3.4). The results were graded on the basis of cleaning and fading as follows: poor (0 to 25 percent), fair (26 to 50 percent), good (51 to 75 percent), and excellent (76 to 100 percent). The mean follow-up period was 15 months. Poor and/or fair results were found in 8 patients who received one treatment and 7 patients who had two treatments. Good results were seen in 1 patient who had two treatments, 7 patients who received three treatments, and 3 patients who had four treatments. Twenty-one patients had excellent results after three or more treatments of the whole lesion. In conclusion, this laser system produces clinically significant fading of nevus of Ota in patients without complications such as hypertrophic scarring or permanent changes in the normal skin pigmentation.