OBJECTIVES: It is important that a questionnaire can detect impact on HRQoL when the disease is ‘active’ and when is not active in patients with Psoriasis. We have developed a new questionnaire where the items have been created to evaluate the impact of the disease in different phases. METHODS: In order to define the main dimensions, a literature review and a F.G with 5 dermatologists were performed. A semi-structured interview was conducted with 20 patients (10 with active and 10 with non active). From the content of the interviews several items were identified. Each item was subsequently rated by the dermatologist. The items were administered to a sample of 171 patients (52.1% active and 47.9% non active). A factor analysis and a Rasch analysis were performed to obtain the final pilot questionnaire before the validation study. RESULTS: After qualitative reduction, a 37 items questionnaire was obtained (score 0; poor HRQoL to 100; good HRQol) (PSO-LIFE 37). Factor analysis identified 6 dimensions (variance explained of 72.4%). Rasch analysis was used to exclude those items with INFIT or OUTFIT > 1.30 and <0.70 or redundant with other items. This final questionnaire (PSO-LIFE 20) has good internal consistency (Cronbach’s alpha=0.94). Comparative psychometric performance between PSO-LIFE 37 and PSO-LIFE 20 showed similar internal consistency (0.97 and 0.94), and item correlation-overall score (0.34-0.82 and 0.35-0.81). PSO-LIFE 20 showed differences (p=0.042) with severity of psoriasis and between patients with active and non active disease (p<0.01) (high score in patients with mild severity, and in patients with non active, which reflect good HRQoL). CONCLUSIONS: PSO-LIFE is a new questionnaire of 20 items, with a priori good psychometric properties though validation is needed through a formal validation process in a sample of adequate size.  Preliminary results show that highest impact on HRQoL is observed in patients with active disease.