THE PURPOSE of this paper is to emphasize the significance and frequency of a transient diabetic syndrome due to and occurring during incipient meningococcic meningitis. This condition was noted among the miscellaneous meningitides as early as 1884. 1 These early observations referred to cases of tuberculous meningitis. The occurrence of glycosuria in meningococcic meningitis has been reported by Box and Nicholson, 2 Bruce and Flexner, 3 Ward and Driver, 4 Hunter, 5 McNally, 6 Cole 7 and Ferguson and Barr 8 (table 1). Observations at South View Isolation Hospital during the last three years have indicated that this syndrome exists in a high proportion of cases of meningococcic meningitis. Findings of sugar and acetone in the urine and treatment of diabetic acidosis impeded the diagnosis of meningococcic meningitis in some instances. When these findings interfere with the final diagnosis of meningococcic meningitis a serious prognosis results. This paper will not involve itself in the diagnostic