In summary, we answer the three questions we have previously posed: (a) Can liver transplantation prolong survival? Evolving data from several centers indicate that liver transplantation indeed prolongs survival in patients with PBC and PSC as compared with estimated survival using disease-specific risk scores based on the natural history of PBC and PSC. (b) Can we optimize timing of liver transplantation? Although many factors enter into the timing of liver transplantation, including when the patient is actually referred for liver transplantation and the individual desires of the patient to pursue liver transplantation, evidence is growing that having patients with chronic liver diseases like PBC and PSC undergo transplantation a little earlier in the course of the disease rather than waiting until the patients have experienced life-threatening complications or are on life-support measures can indeed improve early postliver transplant survival. In patients with PBC and PSC, the survival risk score, which reflects disease severity, can serve as an objective measurement to assess and evaluate the effect of liver disease severity on transplant outcome. Indeed, a number of studies have strongly suggested that optimal timing of liver transplantation may indeed be important to improve outcome, decrease morbidity and decrease cost. (c) Does the present allocation system in the United States allow for optimal use of our scarce donor organ resource?(ABSTRACT TRUNCATED AT 250 WORDS)