Despite the growing professional and academic interest in sustainability and corporate social responsibility (CSR) in recent decades, moral lapses continue to happen in the business arena. Because undergraduate students will be the managers and professionals of the future, training these students to be socially responsible is seen as critically relevant for reducing the likelihood of such moral lapses. However, the question of whether CSR courses can be effective is still debated and little is known about the role that gender may play in this relationship. This study analyzed data from 97 undergraduate students enrolled in a CSR course at a Spanish state university. These data were collected twice, (1) a week before the course had started and (2) a week after the course had been completed. The general lineal modelling (GLM) (repeated measures) procedure in SPSS revealed that CSR courses enhance students’ ethical decision-making. More importantly, the positive impact of these courses is stronger for female students than for male students. Thus, this study demonstrates the positive impact of corporate social responsibility courses on students’ ethical decision making, and sheds light on the target (female students) on which these courses is most effective.