Background: The public health impact of Helicobacter pylori (HP) infection is graduallyrnbecoming obvious, the bacterium now being implicated as an aetiologic agent in a variety ofrngastric diseases. In developing countries, Hp infection is markedly more prevalent at youngerrnages than in developed countries. According to World Gastroenterology Organisation (WGO)rn2010 the prevalence of HP in Ethiopia was 48% in age between 2 4, 80% at the age of 6rnandrn95% in adult s population.rnObjective: To determine the prevalence of H.pylori infection among paediatric patients who srnclinically diagnosed for gastroenteritis.rnMethod: A cross sectional study was conducted to determine the prevalence of H.pylorirninfection among pediatric patient in private pediatric clinic, Addis Ababa Ethiopia. The studyrnwas conduct from March 3rd to May 11th 2014. Non-probability convenient sampling techniquernwas used to collect the data. The stool samples were tested according to the manufacturerninstruction and procedure. Information from the laboratory analysis and questionnaires werernentered into SPSS, version.17 and odd ratio, 95%CI were calculated to measure the degree ofrnrelationship between risk factors for H. pylori infection.rnResult: A total of two hundred twenty one paediatric patients having upper gastrointestinalrnsymptoms because of a suspicion of H. pylori infection participated in this prospective study atrnBeham specialized children s higher clinic between March 2014 and May 2014.Among thernstudy subjects 114(51.6%) were girls and 107 (48.4%) were boys aged from 9months torn15years with the mean age of 6.29 [95% CI 5.9-6.7]. Helicobacter pylori antigens wererndetected in 57 of the 221children giving an overall prevalence of 25.8% (95%CI 18.8-31),rn27.2% in female and 24.3% in male children. The frequency of H. pylori colonization wasrnhigher in females than in males. Of the 114 females enrolled in the study, H. pylori antigen wasrndetected in the stools of 31 (27.2%) against 26 (24.3%) of the 107 males (OR = 0.85rn95%CI=0.46-1.57). Age of acquisition was one year and five month.rnConclusions:rnThe prevalence of H. pylori infection is 25.8%. This is high among children in the study area.rnInfection also is acquired at very early age. Household crowding is one of the factors thatrnenhance the infection.