The current research evaluated metabolic side effects in inpatients (N = 271) using atypical antipsychotic medications in a psychiatric hospital in Turkey between June and December 2016. Data were collected via an information form created after reviewing the literature at the time of patients' hospitalization and discharge. According to the analysis, 73.8% of patients stated they experienced side effects from antipsychotic medications and 20.7% of patients experienced weight gain. A statistical difference was detected among body mass index, waist circumference, diastolic blood pressure, and heart rate during patient hospitalization and discharge. Patients using atypical anti-psychotic medications gained weight, had increased cardiovascular risk, and experienced adverse effects on their physical health during hospitalization. Mental health nurses should inform patients of medication effects and possible side effects, monitor side effects, and teach patients how to manage metabolic side effects. [Journal of Psychosocial Nursing and Mental Health Services, 56(4), 28-37.].