Nurses who try to reduce inequalities in health care by defending individuals they care for should be able to perceive ethical situations sensitively as patient advocates. This study aimed to examine the effects of ethics education provided to nursing students on ethical sensitivity and patient advocacy. The study adopted a pre-test, post-test, one-group quasi-experimental design and was conducted at a public university in Turkey. The sample comprised 44 nursing students taking the Professional Ethics course. Data were collected from October 13, 2021, to January 6, 2022, using a Descriptive Characteristics Form, the Moral Sensitivity Questionnaire, and the Patient Advocacy Scale for Nurses. The study was approved by an ethics committee. While no significant difference was found between the pre-test and post-test mean Moral Sensitivity Questionnaire scores (t = 0.426, p > 0.05), a significant difference was noted between the total mean Patient Advocacy Scale for Nurses scores (Z = - 2.443, p < 0.05). The findings showed that ethics education provided to the nursing students did not affect ethical sensitivity but increased patient advocacy.