An epidemiologic survey of Pediculus capitis infestation among Akka aboriginal and Han children of Chinese refugees living in mountainous areas at elevations of 1,100 to 1,400 m in Chiang-Rai Province of northern Thailand was conducted during January 2003. Of the 303 children examined, 43 (14.2%) had P. capitis infestation. The overall infestation rate for P. capitis in Akka children (29.3%, 12/41) was significantly higher than that in Han children (11.8%, 31/262; chi2 = 8.161, p = 0.002). The prevalence in Akka (52.2%, 12/23) and Han girls (19.7%, 31/157) was higher than that in Akka (0%) and Han boys (0%), respectively (p < 0.001), and the prevalence was higher in Akka girls than in Han girls (chi2 = 10.978, p = 0.001). The high prevalence of P. capitis infestation among these girls was possibly due to poor environmental hygiene and unavailability of sufficient water.