Sarcoidosis is a multisystem disorder that can include ocular lesions. Although the precise etiology of the disease is as yet not well known, it is gradually becoming clearer as a result of much intensive research. The scope of this review is to evaluate the current understanding of sarcoidosis, specifically the pathogenesis of the disease and the therapeutic possibilities.Inherited factors for this disease are gradually being identified by many large-scale genetic studies. As for treatment, biological drugs against inflammatory cytokines, such as tumor necrosis factor-α, are beginning to be used in sarcoidosis patients.The exact etiology of sarcoidosis is still unknown. Further genetic studies in various ethnic populations are required to gain a better understanding of the pathogenesis of sarcoidosis. The data of clinical trials of biological drugs are accumulating, and it is necessary to produce a guideline for the use of these drugs on the basis of the benefits and risks to the patient.