Intussusception is a curious anatomic condition characterized by the invagination of one segment of the gastrointestinal tract into the lumen of an adjacent segment. Once initiated, additional intestinal telescopes into the distal segment, causing the invaginated intestine to propagate distally within the bowel lumen.The aim of the study was to evaluate the clinical manifestation, etiology, and outcome of intussuception at atypical ages.Material and methods. This retrospective study was carried out on patients aged <6 mo or >2 yr with intussusception. Duration of study was from March, 20, 1997 to March, 20, 2008. The places of study were Imam Khomeini and Abuzar referrals hospital. Cases were classified according to age and sex. According to age, patients were <6 mo, 2-10 years, 10-18, and more than 18 years. Age, sex, history, chief complaint, clinical manifestation, sonographic findings, duration of clinical manifestation, method of treatment, outcome, duration of hospital staying, and ICU admission were studied. Data were analyzed with SPSS ver 16 (Chicago, IL, USA) and Epi-info.Results. In this study, 36 cases with diagnosis of intussusception at atypical ages, <6 mo or >2 yr, were included. From all cases, 21 cases (58.3%) were 2 through 10 years and male: female ratio was 2.26:1. Ten cases (27.8%) had history of medical condition. Eighty percent (29 cases) had abdominal pain and 20 cases (58.3%) had vomiting. Abdominal mass was found in 14 cases (38.8%). Sonography was done for 30 (83.3%) of cases and suggesting intussuception in 25 (69.4%) of cases. Intussuception was reduced by hand and performed appendectomy for 10 cases (27.8%). Bowel resection was done for 19 cases (52.8%) and radiological reduction was done for 2 cases (5.6%). Eighteen (50%) cases had anemia. Twenty-five cases admitted to ICU. One (2.8%) patient died (a 65 year old woman). Appendicitis is the most common well defined injury associated with intussusception.Conclusion. This study showed that with advancing age, incidence of intussusception will be decreased. As age increasing, rate of bowel resection will be increased. All cases with appendectomy and reduction by hand had hospital staying 3-10 days. The results of this study was similar to other studies. The most widely used diagnostic procedure for intussusception was sonography.