As a preliminary step to beginning to assess the usefulness of clinical vignettes to measure ethical sensitivity in undergraduate medical students, five clinical vignettes with seven to nine ethical issues each were created. The ethical issues in the vignettes were discussed and outlined by an expert panel. One randomly selected vignette was presented to first, second and third year students at the University of Toronto as part of another examination. The students were asked to list the issues presented by the (...) patient problem. Responses from 281 students were obtained. These students identified an average of 2.72 ethical issues per vignette. Each response was classified under the domains of autonomy, beneficence and justice. Comparisons were made between classes and between vignettes. There was considerable variation between classes and the responses to different vignettes seem to indicate that different vignettes measure the various domains in different ways. It does appear that the use of vignettes is one way to measure aspects of ethical sensitivity in medical students but more study is required to clarify exactly what is being measured. (shrink)