Most research designed to explore undergraduate nursing students' attitudes towards mental health nursing tends to uphold clinical experience as the decisive factor, with much less attention paid to the theoretical component. This paper presents the findings of a state-wide study conducted with undergraduate nursing students in Victoria, Australia. A pre- and post-test design was used to measure students' attitudes toward people with a mental illness and toward mental health nursing and their sense of preparedness for mental health practice. A questionnaire was administered at two time points; the first time point was following completion of the mental health nursing theoretical component, and the second was following the completion of clinical experience. An additional scale was added at the second time point to evaluate students' opinions about their clinical placement. The findings indicated significantly different attitudes and opinions depending on the university students attended. The amount of theory undertaken in the course accounts for some, but not all, of this variance. However, generally the students taking courses with a larger theoretical component tended to demonstrate higher scores (suggestive of more favourable attitudes) on all of the subscales, and that these differences were sustained following the completion of the clinical placement. These findings suggest that the amount of theory students receive in mental health nursing may be more influential than the relevant literature suggests.