PURPOSE OF REVIEW: Several studies have investigated fatigue among sarcoidosis patients. The purpose of this review is to analyze published data on the assessment, prevalence, etiology, and treatment of sarcoidosis-associated fatigue. RECENT FINDINGS: Fatigue was identified as a prominent problem in sarcoidosis, and its presence was frequently associated with impaired quality of life, compared with patients without fatigue. Although the studies with good methodological fatigue assessment found no relationship between clinical parameters and fatigue in sarcoidosis patients, the remaining studies reported associations between fatigue and clinical and psychological parameters. No studies were designed to analyze the etiology of fatigue, but some studies showed that prednisone-treated patients reported more fatigue compared with untreated patients. In addition, only one study focused on a treatment for fatigue, dexmethylphenidate hydrochloride. Several instruments to measure fatigue were used, with the Fatigue Assessment Scale most frequently utilized. SUMMARY: This review illustrates the importance of fatigue as an under-recognized complication of sarcoidosis. It further emphasizes the need for longitudinal prospective studies to better define sarcoidosis fatigue, explore its impact on quality of life, define aggravating or alleviating factors and evaluate new potential treatment strategies.