Sarcoidosis is a chronic granulomatous inflammatory disorder of unknown origin with heterogeneous outcome. In most cases the disease is self-limited, others progress or die from organ involvement, which is often associated with extensive scarring. Although often the primarily affected sites are the lungs and thoracic lymph nodes patients with sarcoidosis must be staged for multiorgan involvement. Modern treatment strategies appraise a critical awareness for the side-effect-ratio of long-term medication. A main interest of research is to identify those patients with unfavourable outcome.