IBD are chronic disorders of digestive tract. Their etiopathogenesis is uknown, but genetic, immunological, environmental and infectious factors play important role. They include CD and UC. IBD impair patients quality of life and require chronic treatment. HLA-G is a HLA-I class antigen, characterized by limited tissue distribution and presence of soluble and membrane-bound izoforms. Different expression of HLA-G antigen izoforms was well documented in many autoimmunological, infectious and neoplasmatic diseases. It is connected with tolerance state against cellular immunological reactions. The aim of this study was to evaluate levels of sHLA-G in serum of patients with CD and UC, to determine the relationship between sHLA-G in serum and the degree of activity of IBD and treatment, and also to determine whether the evaluation of sHLA-G can be a potential biochemical marker, useful in the differentiation between CD and UC. We enrolled to the study 150 patients, including 57 patients with CD, 51 patients with UC and 42 with IBS. In all subjects blood morphology, albumin, total protein, iron and CRP levels in serum were assesed. sHLA-G concentration was determined by ELISA test.The differences in sHLA-G concentration in serum were found not statistically significant in patients with CD, UC and control group. There was a clear effect of immunosuppressive therapy on the concentratio ; n of sHLA-G in patients with active phase of disease. Our results call into question the value of sHLA-G as a biochemical marker, used to differentiate between the CD and UC.