A fatal case of gonococcus endocarditis with detailed autopsy findings is reported. Acute endocarditis followed a urethritis and affected an aortic valve which was already damaged by rheumatism. In addition to acute vegetative endocarditis of the aortic valve, autopsy revealed chronic productive changes in both mitral and aortic valves, subendocardial abscess with extension to the pericardium, diffuse suppurative and hemorrhagic pericarditis, acute intracapillary glomerular nephritis, acute focal interstitial nephritis, parenchymatous degeneration of the kidneys, infarction and suppuration of the spleen, degeneration and congestion of the liver, suppurative gastritis, pulmonary congestion, bilateral hydrothorax, ascites, conjunctival petechiae, suppurative leptomeningitis, gangrene of the legs, and a decubitus ulcer.