The goal of this study was to compare depression and quality of life in three auto immune diseases: psoriasis, vitiligo, and alopecia areata. From January 2009 until January 2010, 300 patients (100 with alopecia areata, 100 with psoriasis and 100 with vitiligo) who were randomly selected (by simple random selection) from outpatient clinic of Razi Hospital (Center of Skin Diseases of Tehran University of Medical Sciences) were asked to answer to Beck Depression Inventory (BDI), SF-36 and Dermatology Life Quality Index (DLQI) questionnaires. DLQI scores were significantly higher in psoriasis cases than others (12.8 ± 6.1, P<0.0001) and SF-36 score were significantly lower (59.8 ± 19.5, P=0.007), both indicating poor quality of life. Significant correlation was found between DLQI and BDI in all disease groups (r=0.44, P<0.001). BDI scores were the highest in psoriasis group but this difference was not significant (P=0.2). Based on these results, dermatologists should consider psychological aspects of autoimmune skin diseases.