Sarcoidosis is a granulomatous disease of unknown etiology. Standard treatment with immune suppressants such as glucocorticoids is started when vital organ function is threatened. Biotechnology has resulted in new treatments ('biologicals'), in particular monoclonal antibodies, that may be effective in the treatment of sarcoidosis. In patients with sarcoidosis, only the use of monoclonal antibodies that block tumour necrosis factor (TNF) has been studied scientifically, other biologicals hardly at all. TNF-blockers are used at present in patients with therapy refractory sarcoidosis.