Evidence from both experimental and clinical trials indicates that inflammatory mediators are important in the pathogenesis of chronic heart failure (HF), contributing to cardiac remodelling and peripheral vascular disturbances. Several studies have shown raised levels of inflammatory cytokines such as TNF-alpha, IL-1beta and -6 in HF patients in plasma, circulating leukocytes, atherosclerotic lesions, and in the failing myocardium itself. Importantly, this rise in inflammatory mediators does not seem to be accompanied by a corresponding increase in anti-inflammatory cytokines such as IL-10 and transforming growth factor-beta; thus resulting in an inflammatory imbalance in the cytokine network. Traditional cardiovascular drugs have little influence on the cytokine network in HF patients. Results from randomised, placebo-controlled anti-TNF studies suggest lack of effect of such therapy. Although somewhat disappointing, these negative results do not necessarily argue against the 'cytokine hypothesis'; these studies just underscore the challenges in understanding the complex cytokine network in order to develop effective treatment modalities in HF patients. More general immunmodulating treatments, such as pentoxyfylline, intravenous immunoglobulin, thalidomide and statins, have shown promising results in smaller studies, which need to be confirmed in larger studies with hospitalisations and death as the end points. In addition, further research in this area will have to be more precise in identifying the most important 'actors' in the immunopathogenesis of chronic HF.