Professional values are standards for action and provide a framework for evaluating behavior. This study examined changes in the professional values of nursing students between their entrance to and graduation from an undergraduate nursing program. A pre- and post-test design was employed. A convenience sample of 94 students from a university in Taiwan was surveyed. Data were collected from students during the sophomore and senior years. Total scores obtained for the revised Nurses Professional Values Scale during the senior year of the nursing program were significantly higher than upon program entry. The 'caring' subscale was scored highest at both program entry and graduation, but the pre- and post-test scores were not significantly different from each other. The students scored significantly higher on the 'professionalism' and 'activism' subscales at post-test than they did at pre-test. Professional values changed in a positive direction between the beginning of the student nurses' educational experience and their graduation. The results supported the premise that education had a positive effect on these students' professional values but causality could not be assumed.