ObjectiveTo compare attitudes of nursing undergraduates to patients with mental illness before and after learning psychiatric nursing course and provide evidence for the improvement of teaching of the course. MethodsStigma scale to patients with mental illness was used as a questionnaire for collecting data, which was conducted on nursing undergraduates taking psychiatric nursing course between March and June 2012. Paired t-test was used to compare the differences between students' attitudes before and after learning the course. ResultsSignificant difference was found for danger factor (P<0.05), while there was no statistically significant difference in the social isolation factor and social ability factor before and after the psychiatric nursing course (P>0.05). ConclusionPsychiatric nursing course has a great influence on students' evaluation of the danger of patients with mental illness which reduces the discrimination against the patients.