Psoriasis is an inflammatory skin disease that causes lesions known as plaques normally on elbows, knees, scalp and trunk. In severe cases (10-30%), the plaques will grow and merge into one another, covering large areas, with painful skin and/or psoriatic arthritis, leading to achy swollen joints. Psoriasis was associated with metabolic impairment and cardiovascular diseases. Some authors suggested a bidirectional relation between psoriasis and obstructive sleep apneas (OSAS), both associated with sistemic inflammation. We identified 30 patients affected by OSAS and psoriasis. The majority were males, with cardiovascular comorbidities (76%), insomnia or sleepiness at diagnosis (83%) and moderate to severe apnea hypopnea index (>15). We investigated the effects of positive airway pressure (C-PAP) therapy on both diseases in a 5 years follow-up period with multidisciplinar evaluations (polysomnography, serum CRP, Psoriasis Area Severity Index, Dermatology Life Quality Index). Our data support the hypothesis of an improvement of skin lesions and life quality (scales p<0.001) associated with C-PAP therapy and suggest to investigate sleep disorders in psoriasis group.