Widespread academic dishonesty among higher education (HE) students has been a concern for higher education institutes (HEIs). Ethics literature reports that unintentional plagiarism is more prevalent among HE students and the root cause is, limited or no awareness of nuances of ethics concerning plagiarism resulting in poor ethical judgments. This study attempts to examine what is students' ethical reasoning for unintentional plagiarism and how HEIs' ethical awareness efforts impact students' ethical judgments which ultimately shape their ethical behavior. The study also explored whether and how individual-level factors such as intrinsic religiosity, age, gender, and work experience moderate the focal relationships. A longitudinal quasi-experimental field study was conducted. The subjects of the study were 294 postgraduate students of an internationally accredited higher education institution in India. The pretest-posttest design involved a set of experimental manipulations reflecting the HEI's endeavors to explicate the unethical implications of plagiarism.