Cachexia is frequently associated with advanced or terminal cancer states, but it can also develop early during the course of neoplastic disease. This syndrome, which is characterized by body weight loss and negative nitrogen balance, significantly affects patient survival and quality of life. Studies on experimental models have shown that a complex interplay of different factors, such as anorexia, classical hormones, cytokines and other less well defined factors, concur in causing tissue wasting. On the basis of these results, it has been possible to prevent the onset of experimental cachexia by targeting therapeutic interventions at the underlying metabolic perturbations. Anticytokine treatments, either acting centrally or peripherally, have received particular attention, and are currently reaching the stage of clinical trials.