Chronic heart failure is one of a number of disorders associated with the development of a wasting syndrome. The precise mechanisms of this remain unknown, but previous studies have suggested a role for immune and neurohormonal factors. We aimed to investigate in detail the differences in body composition (dual X-ray absorptiometry) and the relationship to candidate biochemical factors of the immune, neurohormonal and metabolic systems in 15 healthy controls, 36 stable non-cachectic and 18 cachectic patients with chronic heart failure. Non-cachectic patients showed reduced leg lean tissue (-9.1%, P<0.01) compared to controls. Cachectic patients had significantly reduced lean (-21.0% vs controls, -19.9% vs non-cachectics), fat (-33.0% vs controls, -37. 0% vs non-cachectics) and bone tissue (-17.5% vs controls, -15.9% vs non-cachectics) (all P<0.0001). Cachectic patients showed a significantly increased cortisol/dehydroepiandrosterone ratio (+203% vs controls, P<0.0001; +89% vs non-cachectics, P=0.0011) and increased cytokine levels (TNF-alpha, soluble TNF-receptor 1, interleukin-6). The levels of catabolic hormones and cytokines correlated significantly with reduced muscle and fat tissue content and reduced bone mass. Peripheral loss of muscle tissue is a general finding in chronic heart failure. The wasting in cardiac cachexia affects all tissue compartments and is significantly related to neurohormonal and immunological abnormalities. Copyright 1999 The European Society of Cardiology.