Transplant units increasingly recognise a need for assistance from psychiatrists and psychologists in the assessment and management of potential transplant recipients and live donors. This arises from the various known associations between mental disorder and the need for transplantation; the intensifying requirement to select carefully among the potential recipients and donors of scarce human organs; and the drive to maximise transplant outcomes by optimising all aspects of treatment after surgery. There is good evidence that careful, protocol-guided selection among potential candidates for transplantation with alcoholic liver disease helps ensure outcomes at least as good as for other forms of liver disease. The evidence base in other areas is less robust, but the principles guiding the psychiatric assessment are broadly the same. There is an increasing need for psychiatric assessment of potential live organ donors, in order to minimise the risks they run, and in the case of altruistic donation this is now mandatory in UK law.