The mean cost of an additional Quality-Adjusted Life Year (QALY) within a National Health Service (NHS) reveals how much health is lost, on average, when services currently provided by the NHS are displaced. This value has been suggested as a proxy of the average opportunity cost required to set a cost-effectiveness threshold when facing fixed budget constraints. In this paper, we generate information on the marginal cost per QALY in the Spanish NHS that can be used to inform a cost-effectiveness threshold using a pannel of quinquennial data for the 17 regional health services.