The Nevus of Ota is a benign dermal melanocytic lesion that has previously proved difficult to treat. Author used the Q-switched ruby laser with a pulse width of 25 nsec and energy fluence ranging from 7 to 8 J/cm2 to treat nevus lesion of 30 patients with Nevus of Ota. And the result to treatment was assessed with photographs.
 The number of treatment was 6-8 times for brownish pigmented area and 8-12 times for bluish pigmented area. After full treatment, 90%(27 patients) showed 90% or greater improvement of the lesion and the remainder 10%(3patients) showed 75-89% improvement of the lesion. No patient had permanent scarring or textural changes.
 In conclusion, Q-switched ruby laser can lead to highly significant improvement of the lesion in Nevus of Ota.