Downsizing at a large state hospital in Maryland was associated with qualitative changes in the resident population, including a higher density of disruptive or disturbed patients on all operating wards and a reciprocal decrease in the proportion of healthier patients whose presence would have added stability to the social structure. This combination created the illusion that psychiatric patients per se had become more dangerous. More likely, the hospital's reduced accommodations fostered retention of the most disturbed patients in greater concentrations.Overcrowding on the wards was more frequent due to admission pressures and ward closures. Specialized treatment wards were discontinued, and their patients were integrated into the mainstream patient population. Paradoxically, although downsizing may result in fewer patients, the need for staffmay not be reduced, given the qualitative changes in the patient population.A historical overview with ten years of circumstantial evidence implicates downsizing as a prime, albeit inconspicuous, contributing factor to the hospital's increased rate of assaultive injuries. The effects of downsizing are slow and insidious, and it may take months or years for the cumulative changes in regrouped wards and bed-space pressures to translate into higher rates of staff injuries.The focus on reducing census and increasing patient turnover that characterizes most efforts to downsize state hospitals has converged with the growing trend favoring biochemical treatments (9). Despite the obvious benefits of medications, they do not necessarily supersede factors associated with the treatment setting, as the painful reality of staff injuries attests.Assaultive injuries to staff are an unavoidable facet of mental hospital work. The most caring and competent treatment teams experience such injuries at some time. Most research in this areaassumes that patient characteristics are the primary factors affecting the risk of assaultive injuries. This paper suggests that the hospital itself has an equally important role. All due emphasis should be given to the treating environment lest it be minimized, fall into neglect, or inflame rather than support those under its care.