The present study describes representations about smoking and practices related to patient smoking among staff of a large public psychiatric hospital. A survey was performed using a specially designed questionnaire. The return rate was 72.4% (n = 155). A large proportion of staff recognized the importance of both smoking status and mental health for patient's well-being (46.9%), and believed that smoking cessation was possible for psychiatric patients (58.6%). However, the role of the psychiatric hospital was perceived as providing information (85.3%) and helping to diminish cigarette consumption (51%), rather than proposing smoking cessation (29.5%). Staff daily practice included reminding patients of smoking restrictions (43.9%), managing cigarettes (46.5%), and nicotine replacement therapy (24.3%). A principal component analysis of tobacco-related practices revealed two main factors (59.8% of variance): basic hospital actions (factor 1) and more specialized interventions (factor 2), which were significantly associated with higher worries about personally developing smoke-related illnesses (Spearman r = 0.38, P < 0.0001). Compared with non-smokers, smokers reported higher perceived vulnerability to develop an illness due to tobacco and a higher level of worry about this. The discussion highlights the need to redefine roles and expectancies of mental health staff, and improve training and collaboration with experts, in order to improve efficiency concerning tobacco issues.