Introduction: Aim: to report and compare, between different age groups, the clinical findings of children and adolescents with inflammatory bowel disease (IBD) under care at a gastroenterology reference center at the largest public hospital in Brazil. Methods: Records of patients diagnosed as IBD from Jan/1980 to Nov/2003 were reviewed. Diagnosis were based on strict clinical, endoscopic, radiologic or surgery and histopathologic criteria. 3 groups were studied according to age of onset of symptoms:GI-24 infants under 2 yrs of age, median 8.5m±7.5m (2m–24m); GII-35 children between 2 and 10 yrs, median 4yrs10m±1yr10m (2yrs4m-11yrs) and GIII-22 patients older than 10 years, median 11yrs5m±1yr8m (10yrs–15yrs10m). Chi-square and Wilcoxon tests were used (p<0.05). Results: 81 subjects, 33 female and 48 male were included. 31 had Crohn’s Disease (CD), 40 Ulcerative Colitis (UC) and 10 Inderminate Colitis (IC). 13 (3CD,10UC) were diagnosed during 1980–1990(P1); 44 (18CD,18UC,8IC) during 1991–2000 (P2) and 24 (10 CD,12UC,2 IC) during 2001–2003(P3). Median age at onset of symptoms was 4yrs10m±4 yrs5m (2m–15yrs10m) and at diagnosis, 7yrs6m±4yrs5m (11m–17yrs). Median interval to diagnosis was 1yr± 2yrs8m (1m–11yrs5m). Bloody diarrhea (71.6%), abdominal pain (67.9%) and weight loss (45.6%) were predominant manifestations. Anal/perineal lesion was present in 17.3%; aphthous stomatitis in 4.9%; joints, skin, and ocular manifestations in 23.5%; liver and tromboembolic diseases in respectively 19.7% and 3.7%. Median ages at diagnosis in GI, GII and GIII were respectively 2yrs8m±2yrs10m (11m–10yrs2m), 6yrs11m±3yrs1m (2yrs10m–15yrs2m) and 12yrs10m±1yr10m (11yrs–17yrs). Median intervals to diagnosis were 2yrs±2yrs6m (2m–8yrs2m), 1yr±3yrs1m (2m–11yrs5m) and 6.5m±1yr6m (1m–7yrs)respectively for these 3 groups (p=0.25). Male-female ratios for GI, GII and GIII w e re 1,1.9 and 1.4 (p=0.5). During P1, P2 and P3, respectively 0.3, 1.3 and 2 .6 cases/year were diagnosed in GI; 0.7, 1.8 and 2,5 cases/years in GII and 0.3, 1.3 and 1,5 cases/year in GIII. In GI, 12(50%) patients were CD, 9(37.5%) UC and 3(12.5%) IC. In GII, 11(31.4%) CD, 20(57.1%) UC, and 4(11.4%) IC and in GIII, 8(36.4%) CD,11(50%) UC, and 3 (13.6%) IC. As to clinical manifestations, no differences were found between these 3 groups. Conclusion: 1.At our Institution, the incidence of IBD is increasing and most remarkably in young infants; 2. Clinical features do not differ between different age groups; 3. In infants, CD is more frequent than UC; 4. Diagnosis of IBD in infants offers no more difficulties than at other ages and it must be considered so that referral and/or diagnosis may not be retarded.