The development and pilot testing of the Professional Decisions and Values Test (PDV) is described. The PDV is designed to assess how ethical conflicts are dealt with by medical and law students and which moral values motivate them. Data from two consecutive classes of entering medical and law students are presented and their action tendencies and ethical values are compared. The findings support the construct validity of the test. Regarding reliability, stability over time is present for action tendencies but not for values. Perhaps the ethical values of entering medical and law students do not become stable until later. Change in ethical values can be studied with the PDV for groups, not individuals, during the first year of professional education.