We introduced a compulsory medical ethics course for first-year medical students so that they would understand the basis of bioethics thinking and acquire the basic capacity to solve patients' clinical problems. The course consists of 14 school hours, of which 11 were for group discussion of 2 clinical cases and 3 were for whole-class lectures on various ethical issues. Identical, short ethics tests were given on the first and last days of the course. The acceptance level was evaluated on the basis of the score of the second test, reports submitted after group discussions, and class attendance. The scores of the second test correlated with the results of reports of the second clinical case but not with those of the first clinical case. Logistic regression analysis indicated that factors contributing to the acceptance level were the scores of the second test and the attendance rate, which was an independent contributing factor. Furthermore, the scores of the second test, but not of the first test, correlated with the acceptance level. These results indicate that this ethics course is useful for increasing students' thinking about ethical issues.