- Obesity and associated medical conditions may have an impact on morbidity and even mortality in patients with psychiatric disorders. The authors present the results of a survey of the prevalence of obesity and selected medical conditions among 420 consecutively admitted psychiatric inpatients at a long-stay facility and compare these data with those reported in the literature. Female psychiatric subjects had considerably higher rates of being either overweight or obese (69%) as compared to women in the general U.S. population (51%). Male psychiatric subjects did not differ significantly from their counterparts in the general population in being overweight or obese (nearly 55%). The majority of psychiatric subjects with essential hypertension, diabetes mellitus, dyslipidemias, cardiovascular disease, or sleep apnea were either overweight or obese (72%–87%). In this cross-sectional study, no associations could be deduced between psychotropic drug classes and specific medical conditions. No specific psychiatric diagnostic category was associated with a significantly greater prevalence of any specific medical condition, except that subjects with schizoaffective disorder appeared to have a higher prevalence of type II diabetes mellitus (11.6%). Subjects with predominant substance or alcohol abuse or dependence disorders had a lower prevalence of obesity and associated medical conditions. Obesity—either independently or additively along with a sedentary lifestyle, unhealthy dietary habits, and nicotine dependence—may have a serious impact on coexisting medical comorbidity in psychiatric patients. Judicious monitoring for obesity and rapid pharmacological and nonpharmacological intervention, where appropriate, by concerned clinicians may improve several coexisting medical conditions in psychiatric patients and thereby improve patients' overall quality of life.