Psoriatic Arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis. The pathophysiology of PsA includes genetic, environmental and immunologic factors. Recent studies revealed the dynamic role of the immune system in the pathogenesis of the disease. Adhesion molecules, proinflammatory cytokines, angiogenic factors and metalloproteinases appear to orchestrate the inflammatory response in PsA. This article summarizes the current immunologic findings and suggests future therapeutic and researching approaches in the field of PsA.