Background: Inflammatory bowel disease (IBD) consists of 2 well-established but not entirely discrete disease entities, Crohn disease (CD) and ulcerative colitis (UC). This study aimed to investigate the serum Intestinal fatty acid-binding protein (I-FABP) as a possible biomarker for the diagnosis, monitoring activity and severity of IBD with & without MAFLD. Methods: This cross-sectional study included 50 patients with IBD who admitted at the Hepatology and Gastroenterology Department of Benha University Hospital. Patients were selected and divided into two equal groups: group 1: (N= 50): patients with IBD, was subdivided according to association with MAFLD based on laboratory an abdominal ultrasound finding into: patients with IBD with MAFLD patients with IBD with no MAFLD. Group 2: (N= 25): patients admitted for colonoscopy for causes rather than UC as a control group. Results: Increased BMI, being smoker, being diabetic patient and increased waist circumference was associated with increased liability of being MAFLD. Each one-unit increase in BMI will cause 1.18-time increase in vulnerability for occurrence of MAFLD. In addition, being smoker alone or diabetic alone will increase risk of being MAFLD 6, and 5.69 times respectively. one unit increase in Waist circumference was associated with 5% risk increase of the MAFLD, none of the disease characteristics affects occurrence of NAFLD in IBD patients. Conclusion: I-FABP is a promising biomarker for the diagnosis, monitoring activity and severity of inflammatory bowel disease in patients with IBD with & without MAFLD.