Ignaz Semmelweis was a Hungarian obstetrician who in the nineteenth century, preceding the discoveries of Pasteur and Lister, proposed the infectious etiology of puerperal sepsis. With a simple antiseptic procedure, he achieved marked reduction of the prevalence of this disease. However, he needed to fight against the reluctancy of his colleagues who didn't accept his observations although they were for the first time in the history of Science, supported by statistical significance analysis. This report describes biographical data of this revolutionary physician and the circumstances of his strange death based on information not often revealed.