Background: Psoriasis is an autoimmune skin disease and associated with other diseases such as cardiovascular, hypertension, and diabetes mellitus. Aim: Our aim was to explore the prevalence of diabetes mellitus and hypertension in psoriatic patients. Materials and Methods: Between April 2008 and May 2010, a total of 304 psoriatic and 300 nonpsoriatic patients were enrolled in this cross sectional study. Data were obtained on age, sex, weight, heights, etc; documented medical history of diabetes mellitus and hypertension; family history of diabetes mellitus and hypertension in first relatives, history of smoking. Results: There was no significant difference in age and gender distribution between two groups. There was also no difference in body mass index between two groups. Within psoriatic group, 79.3% of patients present with plaque type of the disease and 20.7% present with other types. The results showed that within psoriatic patients, the prevalence of diabetes in women is significantly higher than in men (OR=1.93, CI95%: 1.1-3.6, P=0.004) but this difference is not present in nonpsoriatic patients. The results also showed that the prevalence of diabetes in psoriatic patients is significantly higher than nonpsoriatic patients (OR=1.76, CI95%: 1.11-2.8, P=0.015). The data showed that psoriatic patients were more likely to develop hypertension compared with nonpsoriatic patients (OR=2.2, CI95%: 1.2-4.6, P=0.003). According to results, although smoking rate within psoriatic patients is higher than the other group but the difference was not significant. Conclusion: Psoriatic patients have an increased risk of developing metabolic syndrome and hypertension in comparison to nonpsoriatic patients.