Gajdusek graduated in 1943 from the University of Rochester (New York) , where he studies Physics, Biology, Chemistry and Mathematics. He obtained an M.D. from Harvard University in 1946. He performed postdoctoral research at both Caltech and Harvard before being drafted to complete military service at the Walter Reed Army Medical Service Graduate School as a research virologist.He held a position at the Institut Pasteur in Tehran from 1952 to 1953, where he was excited by the challenges "offered by urgent opportunistic investigations of epidemiological problems in exotic and isolated populations". In 1954 he went to work as a visiting investigator at the Walter and Eliza Institute of Medical Research in Melbourne. It was here he began the work that culminated in the Nobel prize.
Vincent Zigas, a district medical officer in the Fore Tribe region of New Guinea first introduced Gajdusek to Kuru. Gajdusek provided the first medical description of this unique neurological disorder, which was also known as the "Laughing Sickness". He lived among the Fore, studied their language and culture and performed autopsies on Kuru victims. Gajdusek correctly concluded that the disease was transmitted in the ritualistic eating of the brains of deceased relatives, which was practiced by the Fore. Though Gajdusek was not able to identify the infective agent that spreads Kuru, further research led to the identification of rogue proteins called prions as the cause of Kuru. He became head of laboratories for virological and neurological research at the National Institutes of Health (NIH) in 1958 and was inducted to the National Academy of Sciences in 1974 in the discipline of microbial biology.