Pediculosis is an ectoparasitosis infestation that has not received much attention in northern Chile despite it is a common reoccurring condition among school-age children. The objective of this study is to determine the prevalence of Pediculus humanus capitis infestation in elementary schools of Arica. Patients and Method: A group of 665 elementary school students from the Province of Arica were screened between August and November 2010; 467 children who met the inclusion criteria were selected. After parents and students signed an informed consent, the diagnosis was carried out through examination of the head with naked eye in each participating school, recording the presence of Pediculus humanus capitis, infestation level and parasite stage. Results: 40.3% (188) of the children presented Pediculosis; the six schools studied were affected. Pediculosis infestation in girls reached 55.2% (138/250) and 23% (50/217) in boys. Conclusion: The school population of Arica is significantly affected by Pediculosis and its prevalence is similar to other regions.