Recent financial scandals worldwide have intensified concern for business (and especially accounting) ethics. Hence, under an overall economic and social sustainability approach, it is crucial to improve the effectiveness of business ethics and corporate social responsibility (CSR) education, in terms of its impact on business students’ awareness of ethical issues. However, stand-alone business ethics/CSR courses are uncommon in Spanish universities. Accordingly, this paper aims at examining the influence of ethics courses on students’ awareness of business ethics in unfriendly environments. We test our hypotheses, through hierarchical regression, in a sample of 551 management students of a Spanish university. Our results suggest that business ethics/CSR courses increase awareness of the importance of ethics in: (i) business courses, (ii) recognizing accounting ethical implications, and (iii) workplace decisions. Our findings also show that a joint interactive effect of gender (female students) and age (older students) increases the impact of business ethics/CSR courses on students’ awareness of the importance of: (i) ethics in workplace decisions, and (ii) the recognition of accounting ethical implications. Our results also support the relevance of different learning styles and the convenience of adapting ethics/CSR teaching methods depending on students’ characteristics. Research and practical implications are derived from our findings.