Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis. It is classified as one of the seronegative spondyloarthitides. There is a dominant expression of the disease in the peripheral joints, therefore labelled as peripheral spondyloarthritis. However, axial expression may occur in addition to extra-articular manifestations. In this chapter clinical presentation, pathophysiology and imaging is addressed. The role of radiography, CT imaging and MR imaging as well as PET-CT is described. Knowledge of imaging characteristics may help to diagnose early in collaboration with the clinician. The concept of generalized enthesitis is key, in addition to primary features of erosive and proliferative bone changes.