Although Gaffke described Micrococcus tetragenus in phthisical sputum in 1881, the finding of this organism in the spinal fluid is still rare. A search of all the indexed journals discloses only 7 prior cases in the accumulated world literature. Probably the diagnosis of meningitis due to this organism is frequently missed in this country because the symptoms, physical and laboratory findings and clinical course are similar to those of meningococcic meningitis. Reimann 1 in 1934 stated that there were only 2 or 3 reports of any form of infection by M. tetragenus in American literature, in contrast to 170 cases reported in European publications. In recording this case, the eighth, and analyzing the preceding cases, we hope to emphasize sufficiently the similarity to infection with meningococci or staphylococci and to point out the inherent characteristics peculiar to M. tetragenus. A realization of these facts should result in the recognition of