The localized aggressive periodontitis, called an early onset periodontitis, is periodontal tissue destruction that symptoms appear at adolescence and youth that the prevalence of it is different in different areas. The crosssectional present study was done by two-step method on 1000 individuals at 14-16 years high school students. The examination was done in two parts. After isolating samples at office school in normal light, overthrow of the lips and cheeks by tongue blade or mirror examination, the pockets of mesiobuccal, mesiolingual, distobuccal, distolingual, buccal and lingual of first molar and incisors of both jaw were measured by Williams probe. In step two the suspicious student invited to clinic for more diagnosis. Other information was collected by Questionnaire. There were 500 boys and 500 girls that were examined. In the first step of examination, the 32 individuals who suspected were isolated. In the second examination, the 7 persons isolated as patient. The prevalence of that was 0.7% in population. ). The prevalence divided into 0.3% females and 0.4& males. By Chi-square was determined that there wasn`t any significant relationship about gender (p>0.05). In respect of 0.7% prevalence for local aggressive periodontitis in Ilam, Iran and the prevalence around the world about 0.1-0.3%, it can concluded that Ilam has the more prevalence and it needs more healthy services attention.
