Cases of gonococcus endocarditis have been reported not infrequently in the literature. Up to 1912, according to McCants, there were a hundred cases published. Since 1912 we have been able to collect forty-eight cases. Table 1 summarizes the evidence on which the diagnosis of these cases was made. The two cases which had the most complete diagnostic evidence were those of Grenet, Laurent, de Pfeffel and Levent, and of Riecker. In these cases the blood culture, bacteriologic morphology, cultural characteristics, fermentation and agglutination reactions were all positive. Huebschmann's case had a positive history, blood culture, postmortem culture, bacteriologic morphology and cultural characteristics. There were four cases that had a positive history, blood culture, bacteriologic morphology and cultural characteristics (Thayer, case 11, Laserre, Dwyer, Kramer and Smith). Two cases (Vander Veer and Kirkland) had a positive history, postmortem culture, bacteriologic morphology and cultural characteristics, but a negative blood culture. Nine cases