Otto Greither was born on 21 November 1867 in Munich, in the Knödelgasse, which is the present Hartmannstraße. After completing high school, he studied Human Medicine at the Ludwig-Maximilians University of Munich (LMU). The young medical student, thirsty for knowledge and interested in; what was then, still a new research field of hygiene; went on to work as an assistant to the two renowned Munich hygiene researchers, Max von Pettenkofer and Rudolf Emmerich.
After his promotion, he launched his remarkable career, first working as a surgeon at the Hospital of Munich. Based on his good examination results, he received a "special state scholarship" for the Vienna Clinic and he then went on to have a good practice as country doctor. However this work did not fully satisfy him and he made a decision to train further as a neurologist. He started learning again under eminent doctors, this time in Görlitz, Prague and Berlin. In Berlin, he added another field to his knowledge, that of dentistry.