Objective: To determine independent predictors of readmission to a psychiatric hospital in Switzerland. Method: Data on 16,727 hospitalizations of 7,786 patients admitted between January 1, 2007 and December 31, 2019 were collected. Univariate correlates of readmission were identified and logistic regression was used to determine independent indicators of readmission. Results: 2,935 (37.7%) patients were readmitted out of 7,786. The observed population was of 47.5% men and had a median age of 44. Substance use disorders (34.2%) were the most common diagnosis followed by psychotic disorders (31.2%), depressive disorders (29.2%), bipolar disorders (12.2%), and schizoaffective disorders (9.8%). Logistic regression revealed novel independent predictors of readmission including a university or college education (OR = 1.63; 95% CI = 1.08 – 2.48), a BMI ≥ 25 kg.m-2 (25 kg.m-2 ≤ BMI < 30 kg.m-2: OR = 1.43; 95% CI = 1.25 – 1.63; BMI ≥ 30 kg.m-2: OR = 1.84; 95% CI = 1.57 – 2.15), metabolic syndrome (MetS) (OR = 1.57, 95% CI = 1.05 – 2.33), central obesity (OR = 1.81, 95% CI = 1.33 – 2.46), hypertriglyceridemia (OR = 1.59; 95% CI = 1.38 – 1.83), HDL hypocholesterolemia (OR = 1.22; 95% CI = 1.06 – 1.40), and hyperglycemia (OR = 1.58; 95% CI = 1.35 – 1.85). Conclusions: Metabolic syndrome, central obesity, hypertriglyceridemia, HDL hypocholesterolemia, and hyperglycemia were identified as independent predictors of psychiatric rehospitalization for the first time. A conscious awareness of these risk factors especially in psychiatric prescriptions among clinicians and a regular monitoring of metabolic parameters are of critical importance to reduce psychiatric rehospitalization.