摘要Objective To evaluate the clinical response of Nevus of Ota to Q-switched Alexandrite laser, and analyze factors that influence the treatment outcome.Methods A total of 522 patients treated with Q-switched Alexandrite laser were included in the study. Single and multiple variate analyses of various factors were per formed. Results Satisfactory result was observed in all patients, none of whom developed scarring. Clinical response was improved with additional treatment sessions. The clin ical response of the 20-27-week treatment interval group was significantly better t han that of the 12-19-week interval group, but showed no significant difference as compared with both the 28-35 and ≥36-week interval group. Zygomatic, bucc al and frontal areas showed better response than ocular and temporal areas. Tre atment session, interval, and fluence were significant factors identified by mul tivariate analysis. Conclusions Q-switched Alexandrite laser is an ideal method for treating Nevus of Ota without injury. The number of treatment sessions is more important than interval or fluence.