Psoriasis (PSO) is traditionally defined as an immune-mediated, inflammatory dermatological disease characterized by a chronic-relapsing course and associated with multifactorial inheritance (genetic predisposition and influence of various environmental factors). Considered until recently a dermatological disease only, today PSO is correctly known as a systemic one because of the involvement of multiple organs with important impact on social life and relationships. PSO is found in the 0.3-4.6% of the world's population, while its prevalence in the Italian population is estimated at 2.8%. Therefore, if we consider that in Tuscany more than 100,000 people out of 3,672,202 suffer of psoriasis, it is of paramount importance to focus on a shared clinical and therapeutic protocol to manage the disease. With the aim of ensuring diagnostic-therapeutic suitability, high levels of care and standardization of treatment, a unique clinical-therapeutic management model has been developed and validated in Tuscany, involving all accredited regional dermatological centers. Among the possible alternatives to be implemented in the treatment of patients with mild, moderate-severe psoriasis, UVBnb phototherapy is widely used alone or in association with other systemic and non-systemic devices. Despite this, there is still no universally shared therapeutic protocol. In this context the CO.FO.TO working group (Consensus Fototerapia Toscana) is born with the aim of defining and validating the main guidelines in the use of phototherapy with UVBnb in psoriasis; the guidelines are based both on the real-life experience of the different centers of reference in the region and on the revision of the recent literature.