Patients with alcoholic liver disease often complain of restricted physical capacity, which could be due to decreased muscle endurance. The aim of this study was to assess the muscular endurance in patients with alcoholic liver disease. In a cross sectional study, 24 patients with alcoholic liver disease and 22 controls were evaluated using isometric dynamometry. Endurance was determined during contractions for 3 min elicited by intermittent external electrical stimuli to the femoral quadriceps muscle. Second, endurance was evaluated during voluntary contractions by performance of a maximal isometric knee extension maintained for 1.5 min. Although no difference between patients and controls was found for voluntary contractions, the patients did have lower involuntary muscular endurance. Muscular endurance was not related to lean body mass. Maximal voluntary isometric muscle strength and total work of knee extensors were almost halved in the patients and lower also after correction for differences in lean body mass. In addition to low-muscle strength, patients with alcoholic liver disease have lower involuntary isometric muscular endurance unrelated to lean body mass.