Sarcoidosis-associated fatigue is globally recognised as a disabling symptom. Fatigue has been reported in up to 50-70% of sarcoidosis patients, causing impaired quality of life. The aetiology of this troublesome problem remains elusive and is usually multifactorial. Fatigue can be a consequence of treatment itself, including as a complication of corticosteroid therapy. The diagnosis of sarcoidosis-associated fatigue requires an extensive evaluation to identify and treat potentially reversible causes. Granuloma formation and cytokine release may be involved in its aetiology. However, despite adequate sarcoidosis treatment, many patients continue to experience fatigue. Comorbidities associated with sarcoidosis, including depression, anxiety, hypothyroidism and altered sleep patterns, may all contribute to fatigue. Despite an exhaustive search for treatable clinical causes of fatigue, most patients' complaints of fatigue are not correlated with clinical parameters of disease activity. Recent studies have demonstrated the effectiveness of various neurostimulants, including methylphenidate, for the treatment of sarcoidosis-associated fatigue. These and other agents may be useful adjuncts for the treatment of sarcoidosis-associated fatigue. Obviously, there is a need for studies evaluating the causes and new therapeutic options of sarcoidosis-associated fatigue. Psychological interventions should also be examined.