Smoking is widely recognized as an important public health issue for the general population and in the mental health field where the rates are particularly high. Mental health nurses are well positioned to take an active role in encouraging and supporting people diagnosed with mental illness to cease smoking. Information about smoking behaviour and the attitudes of mental health nurses is necessary to develop strategies to prepare nurses for this important role. A cross-sectional study was conducted to examine the smoking behaviour and attitudes of mental health nurses in Queensland, Australia, through a random selection of mental health nurses (n = 289). Smoking rates(16%) in this study were lower than those for the Australian population. Smokers were significantly (P < 0.001) less likely to agree that health-care facilities should promote a healthy environment. All participants, but predominantly those who smoked (P < 0.001), supported the individual’s right to smoke. Participants believed they possessed appropriate skills to deliver the antismoking message effectively, although stronger beliefs were characteristic of non-smokers. Participants who smoked perceived that their smoking status assisted in facilitating interactions with consumers (P < 0.001). The findings have implications for the health promotion activities of mental health nurses.