The clinical and laboratory findings, and the results of treatment of 16 Meningococcal meningitis cases, who were hospitalized, are investigated, and discussed with the literature. On application all of the patients had headache, meningeal irritation findings, and fever (% 75), nausea and vomiting (% 62.5), rash (% 56.25), unconsciousness (% 50), coma state (% 31.25), Herpes labialis (% 31.25), affecting of cranial nerves (% 12.5), arthritis (% 12.5), and carditis (% 6.25). At the peripheric blood examinations, all had leucocytosis, and neutrophilia. In the direct examination of the cerebrospinal-fluid, in 15 patients gram negative diplococci were seen, and in 11 patients the microorganisms grew on culture. The patients were given Crystalized-Penicillin in doses of 20-30 million IU/day. In the two cases some complications, resistance, and allergy developed, so the treatment changed. Only a patient died, and in the other cases no relapse and sequel were seen.