A lot of studies show the efficacy of thermal therapy in psoriasis. The main indications concern all forms of psoriasis (except for pustolosa and eritrodermic) especially diffuse psoriasis, intensive itchy, artropatic psoriasis and gutted psoriasis child. Benefit effects of thermal water and muds, which are important parameters in psoriasis' treatment, they are excellent to reduce inflammation, scaling, and erythema. In this study we evaluated the clinical efficacy of thermal bath plus muds in patients affected by psoriasis. 18 patients has been examined and randomly divided in 3 group (A-B-C). All the patients received thermal therapy for 4 weeks. To evaluate the behaviour of the disease we performed (corneometry, sebometry, phmetry), as well as evaluation of P.A.S.I. At the end of the study, values of P.A.S.I. showed a reduction from 10 to 6 unites P.A.S.I. for patients belong to group A, more 12 to less 10 for patients belong to group C e no significant variations for group B (because represent control group). Results obtained can be considered useful, considering that thermal treatment was used alone in the treatment of all patients.