This study examines attitudes of mental health professionals about the use and usefulness of depot antipsychotic medications and determines similarities and differences in attitudes between professional groups. Mental health professionals working with patients with severe mental illness completed a questionnaire designed to evaluate their opinions concerning rate of depot use, indications for use of depots, problems with use of depots, common side effects of depots, barriers to switching from depot to oral atypical antipsychotics, impact of staffing levels on drug choice, and relative confidence in various antipsychotics for the management of chronic psychosis. Overall, all professional groups perceived depot antipsychotics as a requirement for the treatment of those with serious mental illness who were poorly adherent. However, there were a number of professional differences in responses to certain items in the survey that probably reflected the degree of direct contact with patients. Medical staff were remarkably uniform in their opinions on the use and usefulness of depots. Mental health staff from all the professional groups surveyed considered extrapyramidal side effects (EPS) a major concern, while few rated cognitive side effects, sexual side effects, and weight gain as significant concerns, even though these problems are reported to be a principal concern of patients. Although all professional groups indicated an awareness of the potential toxicity of depot antipsychotics and there was an overall consensus that atypical antipsychotics are likely to be beneficial in chronic psychosis, limitations in resources were seen as a barrier to switching. Attitudes concerning the usefulness and rationale for use of depot antipsychotics differ by medical profession. Nursing and allied health workers are more likely than medical staff to note patient specific variables such as weight gain, injection site reactions, and patient preferences as problems with depots. The results also suggest that, in a community-based psychiatric care system, the use of newer and potentially better agents for the management of psychosis is impaired by resource limitations in service delivery as well as by educational disparities between the professions.