Malnutrition is common in patients awaiting liver transplantation and may contribute to operative and post-operative mortality, although this is controversial. We assessed the pre-operative nutritional status of 87 patients and the impact this had on mortality and morbidity following liver transplantation for chronic liver disease. Thirty six per cent of patients had more than 10% loss of body weight prior to transplantation. Nutritional depletion, considered present if triceps skin fold thickness or mid-arm muscle circumference were < 5th percentile, was present in 17% and 15% of the total group respectively. Patients whose pre-operative body weights were < 90% of their ideal body weight (IBW) had a longer hospital stay (p = 0.001) and required longer post-operative ventilatory support (p = 0.033). This group also required significantly more treatment with intravenous antibiotics (p = 0.001) suggesting an increased incidence of infective complications. Patients who were obese pre-operatively (body mass index > 30Kg/m2) also required a longer period in high dependency (p = 0.0003). No individual nutritional variable correlated with mortality. In the Irish population undergoing liver transplantation, we found a relatively low prevalence of malnutrition in comparison with other studies. Both under- nutrition and obesity significantly affected morbidity and length of hospital stay post-transplant, although no individual nutritional variable predicted survival post transplant.