Acute meningococcemia is a dramatic clinical syndrome from infection with the gram-negative diplococcus, Neisseria meningitidis. Although pericarditis may complicate the course of meningococcemia, it is distinctly unusual as a presenting sign. A case of disseminated meningococcemia presenting as acute myopericarditis is reported. The serotype isolated, type W135, was a sporadic cause of N. meningitidis in the Boston area. Although the patient had meningitis, bacteremia, and myopericarditis, his course was uncomplicated with early institution of antibiotic therapy.