Objective:To study the clinical effect of epidermal pigmented dermatoses treated by the frequency - doubled Q - switched Nd:YAG laser. Methods:361 cases with ephelides, seborrheic keratosis, lentigines, cafe aulait macules, pigmentation - polyposis syndrome were treated by the frequency - doubled Q - switched Nd:YAG laser. Several times of treatment could be done if the pigment was not removed after a single irradiation. The time of interval treatment was 3 months. Results:169 cases with ephelides, 9 cases with lentigines and 1 case with pigmentation - polyposis syndrome were cured after 1 ~ 2 times of treatment. Of the 123 cases with seborrheic keratosis, 103 were cured and 17 had marked effect after 1 ~ 4 times of treatment. Of the 59 cases with cafe au lait macules, 12 were cured and 19 had marked effect after 1 ~6 times of treatment. No scars appeared in all patients. Conclusion:The frequency - doubled Q - switched Nd:YAG laser is secure and efficient in treating epidermal pigmented dermatoses.