Aim. There are some reports about the relatively frequent occurrence of depression in the case of psoriasis and some hypothesis about interactions between those two diseases. However there are no studies verifying those hypothesis based on reliable structured psychiatric interviews according to the current diagnostic criteria of mental disorders. The aim of the study was to compare the frequency of depression in patients suffering from psoriasis and from other chronic skin diseases with the use of a structured questionnaire for the diagnosis of the main mental disorders Mini International Neuropsychiatric Interview. Method. 32 consecutive outpatients (9 males and 23 females), age M=43.9 with psoriasis were examined by a team of dermatologists, psychiatrists and a psychologist using a standard set of methods. In addition, 32 patients with other chronically occurring skin diseases, including 11 males and 21 females, age M=31.6, were also examined and formed the control group. Results. The point prevalence of mental disorders was significantly higher in the psoriatic group - 20 (62.5%) versus 5 (15.62%) in the control group (p<0.001). In all of the cases, affective disorders were diagnosed. Mild anxiety disorders were additionally found in 10 psoriatic patients (31.25%) and in 2 controls (6.25%) (p<0.001). The level of depression was much higher in the study group than in the control group, both in the Beck Depression Inventory (M=15.28, SD=8.72 versus M=8.13, SD=6.31, p<0.001 respectively) and in the Hamilton Rating Scale for Depression (M=9.63, SD=5.71 versus M=5.09, SD-4.26, p<0.001 respectively). The neurotic symptoms measured by the Symptoms Check List-II by Aleksandrowicz were also significantly more intense in the psoriatic group (M=54.37; SD=40.99) than in the control group (M=35.28; SD 23.96) (F=8.55, p<0.005). Conclusion. The results imply the need for the careful examination of the mental state of patients with psoriasis in order to offer and provide treatment of any concomitant psychiatric conditions.