Background & Objectives: Pediculosis (Pediculuscapitis), a parasitic disease, used as an important factor to determine health status of a community. This study was performed to survey the factors concerning with Pediculosis epidemiology among primary-school children of Sari, Mazandaran Province, in 2012-13. Methods: 4712 primary school children (boys and girls) were visited for head lice using cluster sampling method. Data was collected by five trained individuals using a questionnaire that included the information on the diagnostic result of head lice, eggs, and nits infections as well as the sex, age, grade, and residence place. Data were analyzed through chi-square test and the confidence level was set at 95%. Results: Out of 4712 primary school children 78 individuals were infected with head lice. The prevalence of infection was calculated as 1.65%. Significant correlations were observed between prevalence of pediculosis and factors such as bathing facilities, using personal instruments, parents educations, having health care consultant, complying with personal health, and fathers job (p<0.05) while there was no significant relations between head lice infection and hair shape and student grade (p>0.05). Conclusions: The results illustrate the role of education and guidance of teachers and parents towards improving personal hygiene and public health and subsequently on reducing the Pediculosiscapitis rate among school students in the regions studied.