The case of a 38-year-old white female, with a long history of myasthenia gravis, who developed sarcoidosis is presented. The diagnosis of myasthenia gravis had been established on the basis of typical clinical symptoms with severe myastenic crises necessitating respiratory support, characteristic electromyographic findings, positive anti-acetylcholine receptor antibodies and response to appropriate medications. After 9 years of disease and while in apparent remission, she presented with ankle arthritis and bilateral hilar adenopathy. A transbronchial lung biopsy showed noncaseating granuloma, typical of sarcoidosis. To our knowledge, the combination of myasthenia gravis and sarcoidosis is extremely rare and emphasizes the intriguing tendency of some immunologic disorders to appear together in certain individuals.