The effect of "Kangal Hot Spring with Fish" in the treatment of psoriasis is investigated. The study was carried out on 87 patients with psoriasis vulgaris and the patients were evaluated by a dermatologist for 21 days. The evaluation of the disease was performed using PASI (Psoriasis Area and Severity Index) scores. Recurrences were investigated in the patient population, who had been previously treated in the same hot spring. The first examination scores were significantly higher than the scores of the 3, 6, 9, 12, 15 and 21 days after treatment (p < 0.01). Longer remission periods, when compared to the topical corticosteroid treatment, expressed by the 35 patients previously treated in hot spring (p < 0.01). Spa therapy under observation of a dermatologist may be effective and useful for psoriasis vulgaris patients.