Purpose: To examine the differences between characteristics of the work environment of nurses working in mental health and general acute inpatient nursing settings.Design: Secondary analysis of data collected on 96 randomly selected medical and surgical (general) wards and six mental health wards in 24 public acute general hospitals across two Australian states between 2004 and 2006.Methods: All nurses on the participating wards were asked to complete a survey that included the Practice Environment Scale of the Nursing Work Index (NWI-PES). Responses were received from 2,556 nurses (76.3% response rate). Using the five-domain structure, comparisons were made between mental health and general nurses.Findings: Across the entire sample of nurses, those working in mental health settings scored more highly in regard to nurse-doctor relationships and staffing adequacy. Nurses in general wards reported more participation in hospital affairs, stronger leadership, and the presence of more of the foundations of nursing quality care such as access to continued education. Differences between the groups on each of the domains was statistically significant at p=05 or greater, but not for the composite practice environment scale. A wide range of responses was seen when data were aggregated to the ward level.Conclusions: The work environment of mental health nurses is different from that of their colleagues working in general settings. Specific areas of the mental health environment, such as participation in the hospital, leadership, and the foundations of quality, may be enhanced to improve nurses' job satisfaction and, potentially, other nurse and patient outcomes.Clinical Relevance: Factors in the medical and surgical nursing practice environment have been established as significant influences on nurse and patient outcomes. It is important to understand the existence and potential impact of these factors in mental health inpatient settings.