We report the case of a patient with mixed connective tissue disease who presented with two very unusual manifestations of meningococcal disease, cellulitis and endocarditis, concurrently. We also review the literature concerning Neisseria meningitidis as a causative agent of cellulitis or endocarditis. While meningococcal endocarditis or cellulitis is very rare, autoimmune disease predisposes patients to meningococcal infection. Therefore, unusual infections with this organism should be considered in the differential diagnosis of fever and rash in patients with connective tissue diseases.