We report the case of a 2-year-old boy with juvenile sarcoidosis, in whom the cutaneous lesions first arose at the site of and soon after a BCG vaccination. Juvenile sarcoidosis is rare, and the pattern of clinical features is distinct from the adult form of sarcoidosis, possibly related to immunologic development. The cause of sarcoidosis is unknown, although there is much interest in the possibility of mycobacterial species operating as antigenic stimuli to initiate the disease. This case suggests that the Mycobacterium bovis present in the BGC vaccination may have been etiologically important in the development of sarcoidosis. (J Am Acad Dermatol 2003;48:S99-102.)