This paper tests the factorial structure of a questionnaire comprising seven health care rationing criteria (waiting time, ‘rule of rescue’, parenthood of minors, health maximization, youngest first, positive and negative version of social merit) and explores the adherence to them of 254 Portuguese health care professionals, when considered individually and when confronted with two-in-two combinations. Data were collected through a self-administered questionnaire where respondents faced hypothetical rationing dilemmas comprising one rationing criterion and dichotomous options pairs with two rationing criteria. Confirmatory factor analysis and multinomial logistic regressions were used to validate the structure of the questionnaire and the data. The findings suggest that: (i) the hepta-factorial structure of the questionnaire presented a good fit of the data; and (ii) support for rationing criterion depends on whether they are individually considered or confronted in dichotomous options pairs. When only one criterion distinguishes the patients, healthcare professionals support six criteria (by descending order): waiting time, rule of rescue, health maximization, penalization of patients’ risky behaviors, youngest first and being parent of a young child. When two criteria were confronted, immediate threat of life/health and large expected benefits were the most preferred. Conversely, the positive version of social merit was an unappreciated rationing criterion.