Nutritional status was studied in lung transplant (LT) candidates. The hypotheses were that nutritional depletion was highly prevalent and lean body mass depletion was a risk factor for a higher mortality both before and after LT. Of 78 consecutive patients listed for LT, 16 (21%) died while on the waiting list, eight (10%) were alive awaiting LT, and 54 (69%) received a graft. Mean age was 42.3+/-4.4 (mean+/-SD). Thirty-eight per cent had a diagnosis of bronchiectasis or cystic fibrosis (BRO/CF), 33% of emphysema, 20% of idiopathic pulmonary fibrosis (IPF) and 8% of primary pulmonary hypertension. Body mass index (BMI) was 20.4+/-4.3 kg.m2, weight was 87.9+/-16.6% of ideal body weight (IBW). Patients were classed into four nutritional groups according to IBW and creatinine height index (CHI): 1: weight <90% IBW and CHI <60% of predicted (28% of cases); II: weight <90% IBW and CHI > or =60% (27%); III: weight > or =90% IBW and CHI <60% (17%); IV: weight > or =90% IBW and CHI > or =60% (28%). Overall, 72% were depleted corresponding to groups 1, II and III. Lean body mass depletion occurred despite normal weight in 17% of the cases (group III). Subjects with BRO/CF were mostly in groups 1, II, III whereas IPF were concentrated in group II. Lean body mass depletion was associated with more severe hypoxaemia, reduced 6-minute walking distance and a higher mortality while awaiting. After LT, duration of mechanical ventilation, time spent in intensive care unit (ICU) was related to initial body composition. Survival after LT was lowest in group III. To conclude, nutritional depletion in lung transplant candidates is highly prevalent and should be more precisely assessed with a special reference to lean body mass since it has specific consequences both while awaiting and after lung transplant. Attempts should be made to increase lean body mass before lung transplant.