The prevalence of smoking among individuals living with mental illness is high. The purpose of this study was to describe the knowledge, confidence, attitudes, training, nursing practice, perceived overall ability, interest and demographics of psychiatric/mental health nurses regarding tobacco use among psychiatric inpatients. A non-experimental descriptive correlational cross-sectional design was used. Sixty surveys were returned with an overall response rate of 39%. A minority of nurses were knowledgeable about the “5As” of smoking cessation, (Ask about smoking, Advise to quit, Assess readiness to quit, Assist with quitting, Arrange follow-up), a well known intervention framework. Most psychiatric/mental health nurses were confident about assisting patients with tobacco use and attitudes toward intervention were more positive than reported in the literature. However, actual tobacco-related nursing practice was sub-optimal. Minimal tobacco-related training during entry level into nursing practice may be one reason for this situation. Nurses require systemic support to enhance tobacco-related nursing practice.