Comorbidities should be considered in the management of psoriatic arthritis because they contribute to the increase of early mortality, increase the activity of the disease and influence the response to treatment. The aim of the study was the analysis of the frequency and nature of comorbid pathology in patients with psoriasis arthritis of young and middle age. In order to achieve the purpose and objectives of the study, a group of 92 patients with psoriatic arthritis, selected according to the CASPAR (2006) diagnostic criteria, was selected. In patients with psoriatic arthritis of young and middle age, a high frequency of comorbid pathology was observed: in 60.9% of patients, more than one comorbid pathology was observed, with the highest frequency of diseases of the musculoskeletal system. ‑skeletal (42.4%), cardiovascular (41.3%) and diseases of the digestive system (41.3%).