Radiolabelled cytokines and monoclonal antibodies are an emerging class of radiopharmaceuticals for imaging inflammation. These radiopharmaceuticals bind to their targets with high affinity and specificity and therefore have excellent diagnostic potential for imaging of patients with chronic inflammatory diseases. One of the key cytokines involved in the process of inflammation is tumor necrosis factor alpha (TNFα). With the introduction of anti-TNFα monoclonal antibodies over the past decade, treatment of inflammatory diseases has evolved, which allowed remarkable advances in controlling signs and symptoms of inflammation and in slowing destruction. However, drugs may lose efficacy over time in patients or induce adverse events. Using immediately the right medication tailored to the patient's molecular status avoids unnecessary costs and side effects. Significant differences in mechanisms of action and in therapy outcome, depending on the disease to be treated, exist among the different TNFα antagonists. Labelling these agents may help to find out if TNFα is present in the inflammatory process and will therefore help in therapy prediction and stratification in the individual patient. This review describes the role of cytokines and in particular of TNFα in the process of inflammation as well as the influence of TNFα in some well-known and common inflammatory diseases, such as rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel diseases, psoriasis and sarcoidosis. The main focus of this article is to review the role of molecular imaging with radiolabelled anti-TNFα monoclonal antibodies for diagnostic purposes, and in therapy precision, decision-making and evaluation.