The predictors of attitudes regarding academic plagiarism were investigated in Hong Kong secondary school students. The participants were 257 Grade 10 and 11 students who were taking liberal studies. Quantitative analysis showed that the students were unfamiliar with what actions constituted plagiarism. The best predictor of attitudes was the perceived descriptive norm regarding plagiarism (i.e., perception of the frequency of plagiarism in one's environment). We explain this finding by applying the cultural-self perspective and present our recommendations for teachers.