ABSTRACT: Chronic inflammatory diseases, such as inflammatory bowel disease—namely, Crohn’s disease and ulcerative colitis—psoriasis, multiple sclerosis, rheumatoid arthritis, and many others affect millions of people worldwide, causing a high burden of disease, socioeconomic impact, and healthcare cost. These diseases have common features including autoimmune pathogenesis and frequent co morbidity. The treatment of these chronic inflammatory diseases usually requires long-term immunosuppressive therapies with undesirable side effects. The future of chronic inflammatory disease prevention, detection, and treatment will be greatly influenced by the use of more effective biomarkers with enhanced performance. Given the practical issues of collecting tissue samples in inflammatory diseases, biomarkers derived from body fluids have great potential for optimized patient management through the circumvention of the abovementioned limitations. In this chapter, peripheral blood, urine, and cerebrospinal fluid biomarkers used in chronic inflammatory conditions are reviewed. In detail, this chapter reviews biomarkers to fore used or emerging to be used in patients with chronic inflammatory conditions. Those include inflammatory bowel diseases, chronic inflammatory conditions of the liver, biliary tract, pancreas, psoriasis, atopic disease, inflammatory skin diseases, rheumatic diseases, demyelination, and also the chronic inflammatory component of various other diseases in general medicine—including diabetes, cardiovascular disease, renal disease, and chronic obstructive pulmonary disease. Development of personalized medicine is closely linked to biomarkers, which may serve as the basis for diagnosis, drug discovery, and monitoring of diseases.