Gajdusek's father, Karol Gajdusek, was a butcher, an ethnic Slovak from Büdöskő, Kingdom of Hungary (now Smrdáky, Slovakia). His maternal grandparents, ethnic Hungarians of the Calvinist faith, emigrated from Debrecen, Hungary. Gajdusek was born in Yonkers, New York, and graduated in 1943 from the University of Rochester, where he studied physics, biology, chemistry and mathematics. He obtained an M.D. from Harvard University in 1946 and performed postdoctoral research at Columbia University, the California Institute of Technology, and Harvard. In 1951, Gajdusek was drafted into the U.S. Army and assigned as a research virologist at the Walter Reed Army Medical Service Graduate School. In 1954, after his military discharge, he went to work as a visiting investigator at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia. There, he began the work that culminated in the Nobel prize.