Background: There were many studies reported deficient vitamin D in patients with inflammatory bowel disease. Objective: Our study aimed to examine the relationship between vitamin D levels and clinical disease activity in patients with inflammatory bowel disease (IBD). Patients and Methods: A prospective study was conducted at IBD Outpatient Clinic of Al-Rajhi University Hospital of Assiut University Hospitals in period from May 2018 to May 2019. The study enrolled 54 patients with known IBD. In addition to reviewing the demographic and clinical data, serum vitamin D was measured in all patients. Results: Mean age of enrolled patients was 34.24 ± 11.71 years with range between (14 - 67) years. Females were more than half of participants (51%). Mean serum vitamin D level was 43.45 ± 33.91 ng/ml. 20 IBD patients (37%)  were deficient in vitamin D, 4 (7.4%) patients had insufficient level and 30 (55.6%) patients had normal level. Patients with deficient vitamin D had significantly higher C-reactive protein in comparison with those with insufficient level and those with normal level.Patients on conventional therapy or biological therapy had insignificant differences as regard level of vitamin D and its status (P> 0.05). There is a non-significant differences as regard level of vitamin D and disease activity, but the level of vitamin D were lower in active patient than non-active one. Conclusion: Vitamin D insufficiency was uncommon among IBD patients, especially in those with Crohn's disease, and was linked to a stronger inflammatory response as well as more active illness.