Progress in our understanding of the scientific basis of granulomatous inflammation in sarcoidosis provides a framework for enlightened treatment decisions. Current evidence supports the concept that the pathogenesis of sarcoidosis involves a highly polarized T-helper 1 (Th1) immune response to pathogenic tissue antigens. Conventional treatment is focused on attenuating granuloma formation with antimalarial drugs that inhibit antigen presentation or with nonspecific anti-inflammatory agents such as glucocorticosteroids, methotrexate, or azathioprine. Anti-tumour necrosis factor (TNF)-alpha agents such as pentoxifylline, thalidomide, etanercept and remicade, have recently shown some successes in sarcoidosis. Designing future therapies depends on improved knowledge of the critical immunological processes operative in different stages of disease.