Background: psoriatic arthritis (PsA) is a chronic, inflammatory, progressive joint disease. It has much psychosocial impact and affects quality of life (QOL) of the patients. Aim of the study: to determine the psychosocial impact of PsA on the patients and to define QOL of them. Patients and Methods: the study was conducted on 50 PsA patients, 68 psoriasis (Ps) patients, and 100 controls. A case-control, clinic-based study design was used in this research. An interviewing form and Middle Sex Hospital Questionnaire were used to survey the characteristics of the patients and controls. Severity of PsA was determined clinically. Also, the medical outcomes study 36-item short form (SF-36) was used to assess impact of the disease on the patient's QOL. Results: most (92.0%) of PsA patients had psychiatric symptoms. The disease had interfered with most of patients' personal feelings and relationships, daily activities, school/work, and leisure/sport. Majority (88.0%) of the patients had stigma feeling. Also, 40.0% and 60.0% of PsA patients had severe and mild forms, respectively. The differences between two forms of PsA regarding interference with school/work and presence of suicidal ideation were significant. The difference regarding presence of familial psychological stress was significant. The highly affected SF-36 domain scores were general health and physical limitation. The eight mean domain scores were significantly lower among PsA patients than controls. The mean domain scores of physical functioning, physical limitation, social functioning, emotional limitation, and mental health were significantly lower among patients with severe PsA than those with mild PsA. The eight mean domain scores were significantly lower among PsA patients than those with only Ps. Conclusions: the physical and psychosocial aspects of PsA may interact and influence one another. So, PsA has a great effect on the patients' QOL; disrupting physical and psychosocial aspects, and interfering with daily activities, school/work, and leisure/sport. QOL scores were significantly lower among PsA than only Ps patients.