BACKGROUND Psoriasis is a chronic disease with worldwide prevalences of 0.6-4.8%. Its inherent chronic inflammatory component predisposes patients to cardiovascular and metabolic diseases. OBJECTIVES This study aimed to evaluate the associations of psoriasis with comorbidities and health risk factors such as smoking and alcohol intake, and to examine demographic differences in its occurrence in a southern Brazil population. METHODS A case-control study was conducted at the Hospital de Clínicas de Porto Alegre between April 2009 and March 2011. The sample comprised 350 patients with psoriasis and 346 healthy control subjects. Data were collected using a standardized questionnaire. Tobacco load and alcohol consumption per person were investigated. Physical examination included blood pressure, waist circumference (WC), and body mass index (BMI) calculation. Clinical evaluation investigated whether psoriasis was localized or widespread and the percentage of body surface area (BSA) affected. RESULTS Psoriasis patients exhibited an increased WC (P < 0.01) and BMI (P = 0.01) and higher incidences of smoking (P < 0.01) and depression (P < 0.01) than control subjects. A comparison of patients with involvement of <20% and >20% of BSA revealed significant differences in prevalences of hypertension (P = 0.03) and diabetes (P < 0.01). CONCLUSIONS The present study demonstrated higher incidences of depression, increased WC, overweight, obesity, and smoking in psoriasis patients compared with controls. Patients with >20% of BSA affected were 1.69 times more likely to have hypertension and 2.9 times more likely to have diabetes. Healthcare providers should be alert to the increased cardiovascular risk and metabolic specificities of patients with psoriasis. Appropriate information on healthy lifestyle habits, including maintenance of a healthy weight and participation in physical exercise, and avoidance of alcohol and smoking are fundamental.