Inflammatory bowel diseases (IBDs), which include Crohn's disease (CD) and ulcerative colitis (UC), are a group of idiopathic, chronic and relapsing inflammatory disorders of the gastrointestinal tract, whose incidence and prevalence has been increasing in the last decade. This study correlated the circulating cathelicidin levels with mucosal disease activity in patients with IBD.This case control cross sectional study was conducted on 80 adults referred to Gastrointestinal Endoscopy and Liver Unit, El-Haram Hospital. Forty patients had IBD; the others were non IBD patients served as case control. All were submitted to complete medical history, physical examination, laboratory investigations, colonoscopic examination and cathelicidin serum level.The results showed that there was no statistically significant difference between both studied groups regarding both age and sex distribution. In this study we found highly significant decrease in Hemoglobin level in cases group compared to control group (P < 0.001). Also, there was significant increase in platelets level among cases group compared to control (P < 0.05). Also, the serum albumin was decreased among IBD patients compared to control.