The evidence that Adolf Hitler might have suffered from incapacitating syphilis is reviewed. Rumors that he acquired syphilis from a prostitute at the age of 20 years, with possible re-infection during World War I, can no longer be verified. Evidence is that he was sexually rather inactive throughout his life. Suggestions that Hitler's cardiac lesion and complaints such as transitory blindness, tremor of his left arm and leg, recurring abdominal pain and a skin lesion of the leg were of syphilitic aetiology cannot be supported. Hitler's progressive mental and physical deterioration after 1942, his growing paranoia, fits of rage, grandiosity and symptoms of possible dementia would fit in neurosyphilis. There are, however, also other explanations for his terminal syndrome, and evidence that repeated clinical examinations did not show the characteristic signs of dementia paralytica or tabes dorsalis, swings the balance of probability away from tertiary syphilis.