Inflammatory bowel disease is a chronic disease, with unknown etiology, characterized by a sustained inflammatory cascade that gives rise to the release of mediators, capable of degrading and modifying bowel wall structure. The present study investigated changes of circulating metalloproteinases (MMP-3, MMP-9) and CRP levels in patients with ulcerative colitis and Crohn's disease, in order to contribute to the elucidation of pathogenesis. We have studied serum samples of 67 patients, of which 46 with ulcerative colitis (mean age 44.8 years) and 21 affected by Crohn's diseases (mean age 39.52 years), who were hospitalized in the Clinic of Gastroenterology of the Emergency County Hospital of Craiova, Romania. For the quantitative determination of MMP-3, MMP-9 and CRP, the ELISA technique was used. Both patients, with Crohn's disease and ulcerative colitis, showed increased production of studied immunomarkers, which were correlated with some clinical stages, indicating their involvement in the disease activity.