Prognostic models have been developed for patients with primary biliary cirrhosis and primary sclerosing cholangitis to predict survival without transplantation. In patients undergoing liver transplantation, these models have been used in assessing postoperative mortality and morbidity. Recent data suggest that preoperative recipient physiology, such as impaired functional status or renal insufficiency, is the most important determinant of transplant outcome. Survival, quality of life, morbidities and resource use are the key variables to be considered in the timing of transplantation.