New insights into the pathophysiology of psoriasis have suggested possibilities for targeted therapeutic intervention. Several novel, systemic immunomodulatory therapies are currently in clinical development and results of recent clinical trials are remarkable. These include approaches targeting antigen presentation and costimulation, T-cell activation and leukocyte adhesion, the action of proinflammatory mediators and the administration of anti-inflammatory cytokines. These trials contribute to our further understanding of the disease, indicating which mechanisms play a greater or lesser part in its development. Moreover, they will lead to new therapeutic options. If psoriasis is considered as a visible model disease for T-cell-mediated disorders characterized by a type-1 cytokine pattern these recent findings might have a more general impact on the treatment of autoimmune disorders.