OBJECTIVES: To demonstrate the pertinence of using thermal therapy in terms of quality of life. METHODS: During the 2005 and 2006 seasons, a generic scale (SF-12) and a specific scale (DLQI – Dermatology Life Quality Index) were filled in by each patient when they arrived at the Avène hydrotherapy center (consultation on arrival), at the end of the thermal therapy (week 3), but also at 3 and 6 months after the end of the therapy.  RESULTS: These results took into account the 262 questionnaires from patients suffering from psoriasis who filled in the self-questionnaires on arrival. The average age of the subjects was 52.2 ± 13.8 years. The gender ratio was in favour of men (55.3% vs 44.7%). The average age of the subjects at the time of diagnosis was 32.1 ± 16.9 years.66.0% of the subjects considered that their dermatosis had deteriorated “their daily life”, 49.6% “their health” and 49.2% “their leisure activities”. Following the 3 weeks of treatment these feelings had strongly diminished, there were respectively only 35.2%, 26.6% and 30.5% who thought so. The DLQI score on arrival was 26.1 ± 20.2; following therapy it was 10.0 ± 10.5. The evaluation of the DLQI score was compared to the score obtained on arrival, showing a significant improvement in quality of life at 3 weeks, sustained improvement at 3 months and perpetuation of the effect at 6 months (p<0.05). These results show a significant improvement in the mental dimension of the SF-12 (MCS-12 = 39.0 on arrival to 42.5 at following therapy).  CONCLUSIONS: This study confirms the alteration in the quality of life of patients suffering from psoriasis and its impact on daily life. The results confirm the improvement in the patients’ quality of life following the therapy, sustained improvement at 3 months, and perpetuation at 6 months.