In recent years a considerable number of imaging techniques have been used to demonstrate the onset and progression of arthritis-related changes in psoriatric arthritis (PsA). Moreover the identification of new immunological pathways has resulted in a substantial improvement of available therapies for PsA increasing the chance for the individual to receive effective treatment. Although an all-embracing disease activity score is still lacking, there is a variety of symptom-related tools to adequately reflect the course of disease and to evaluate the corresponding treatment success. This manuscript aims to give an overview of the latest corresponding knowledge with respect to PsA.