In this article, long-term prognoses and prognostic factors of patients with sarcoidosis are reviewed. In patients with intrathoracic sarcoidosis, functional impairments and parenchymal lesions at the time of initial examination strongly predicted an unfavorable prognosis. We also discussed the significance of extrathoracic lesions in terms of clinical outcomes of intrathoracic sarcoidosis. In addition, we focused on the genetic approach and the new insights being offering with respect to the disease susceptibility and the development of pulmonary lesions.