Introduction: Clinical activity and inflammatory laboratory index have shown poor correlation with colonoscopy and histology in adults and children with IBD.Clinical activity scores in IBD are partially based upon subjective criteria and are often not reliable.Fecal calprotectin, a dominating cytosolic protein in neutrophyl granulocites,has been associated with the degree of disease activity in IBD in adults and recently in children.Our aim was to establish the correlation of fecal calprotectin with laboratory parameters,colonoscopy,histologic examination and clinical activity scores. Methods: 14 patients (7.5–14 years),9 Crohn’s disease (CD) (ileal and colonic or colonic disease) and 5 ulcerative colitis (UC), underwent colonoscopic examination to evaluate the remission or relapse of the disease and to assess the response to treatment.The following data were obtained: erythrocyte sedimentation rate (ESR, mm/h),C-reactive protein (CRP, mg/L), platelets count (PC, x 103/mm3), fecal alpha1-antitrypsin (A1AT, μg/g) and calprotectin (μg/g), colonoscopic results (grades 0–3), histologic examination (grades 0–3) and clinical activity scoring (0 remission; 1 mild-moderate; 2 severe). Fecal calprotectin was measured using a simple ELISA in spot stool samples. Statistical comparisons were performing using Pearson correlation for parametric data, and the Spearman’s rank correlation coefficient was used for nonparametric data. Results: Data presented: Patient number, UC/CD, calprotectin, a1AT, ESR, CRP, PC, colonoscopy, histology and clinical activity. (1): UC,436,0.7,21,5.6,271,2,3,1. (2): CD,6,0.07,6,0.5,366,0,1,0. (3): CD,286,5,24,23.1,524,1,3,2. (4): CD,341,4.3,11,4.3,451,3,3,2. (5): CD,446,3.7,22,16.5,401,2,2,1. (6): UC,316,1.4,16,4.2,440,2,2,1. (7): CD,283,3.3,18,8.5,182,1,2,1. (8): UC,276,0.19,13,0.5,358,1,2,1. (9): UC,444,0.60,27,0.5,427,2,2,1. (10): CD,216,1.10,16,179,311,1,1,1. (11): CD,107,0.11,18,0.5,162,1,1,1. (12): CD,173,0.29,12,12.1,401,0,2,0. (13): UC,203,1.8,16,4.9,475,2,2,1. (14): CD,272,0.40,58,82.9,476,2,2,1 When making the correlations, the only variables with statistical significance were: Colonoscopy (r=0.687, p=0.007), histology (r=0.650, p=0.012) and clinical activity (r=0.530, p=0.050) Conclusion: Fecal calprotectin correlated closely with macroscopic and histologic inflammation and is lightly associated with disease activity. No correlation was found with the laboratory inflammatory markers. As a simple and noninvasive test, fecal calprotectin reflects the disease activity in IBD and it can be used for monitoring the response to treatment and detecting relapses.