The information on prevalence of obesity, diabetes, metabolic syndrome (MetS) and cardiovascular risk (CVR) and on sociodemographic variables available in patients with psychiatric diseases about to be treated with weight gain-associated medication (e.g., clozapine, mirtazapine, quetiapine) is limited. In a naturalistic study, psychiatric inpatients (age: 18-75) of all F diagnoses according to ICD-10, who were about to be treated with weight gain-associated medication, were included. Demographic variables were assessed as well as biological parameters to calculate the Body Mass Index (BMI), MetS, diabetes and CVR. A total of 163 inpatients were included (60.1% male; mean age: 39.8 (± 15.1, 18-75 years). The three most common disorders were depression (46.0%), bipolar disorder (20.9%) and drug addiction (20.2%). The three most common pharmacotherapeutic agents prescribed were quetiapine (29.4%), mirtazapine (20.9%) and risperidone (12.9%). Of the included inpatients 30.1% were overweight, 17.2% obese, and 26.9% and 22.4% fulfilled the criteria for a MetS according to the International Diabetes Federation (IDF) and the National Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP ATP III), respectively, 3.8% had (pre)diabetes and 8.3% had a moderate and 1.9% a high CVR according to the Prospective Cardiovascular Münster (PROCAM) score. Detailed information is reported on all assessed parameters as well as on subgroup analyses concerning sociodemographic variables. The results suggest that psychiatric patients suffer from multiple metabolic disturbances in comparison to the general population. Monitoring weight, waist circumference, blood pressure and cholesterol regularly is, therefore, highly relevant.