Background: Patients with affective disorder have higher mortality not only because of their affective illness but also because of a higher risk of death from physical illness especially cardiovascular diseases. Aim: To investigate the prevalence in a naturalistic cohort of patient treated at a Mood Disorder Clinic. Methods: Patients were evaluated for the presence of metabolic syndrome (MeS) according to modified NCEP ATP III criteria. Results: Of the 143 patients eligible for participation, 100 patients participated in the study (32% male, mean age 43.6 ± 14.2); the prevalence of MeS was 26%. Higher age and high body mass index (BMI) were significantly associated with MeS. No association between present medication and MeS was seen. Conclusion: More than a quarter of affectively ill patients had MeS, which emphasizes the importance of integrated somatic and psychiatric care in order to reduce this group of patients' risk profile concerning cardiovascular diseases and diabetes. Clinically, it seems reasonable to prioritize overweight and obese patients for further examination.