Ethical problems surrounding organ donation have been discussed since before technologies supported the procedure. In addition to issues on a societal level (e.g. brain-stem death, resource allocation), ethical concerns permeate the clinical practice of health care staff. These latter have been little studied. Using qualitative methods, this study, focused on transplant co-ordinators and their descriptions of dilemmas, ethical concerns and actions in response to them. Interviews with three co-ordinators in Japan and two in the UK revealed five areas in which dilemmas occurred: aspects of discrimination; conditions placed on who should be the recipient and the related issues of directed donation; respect for a person's right to make a decision and the extent of information provided and understood by donors and recipients; potential issues of coercion, compensation and rewards in live-related and live-unrelated donations; and potential conflicts in duties. This study describes the dilemma areas revealed. Their meaning for co-ordinators will be presented in a subsequent report.