In 1946, he traveled to the United States as a visiting professor at Harvard University, where he continued his study of Sanskrit texts.
That same year, he was awarded his PhD from the University of Leiden; his doctoral thesis was a critical translation of Candrakīrti's Prasannapadā.
of Leiden, working at the university's Sinologisch Instituut; in 1956, he became the first Chair of Tibetan and Buddhist Studies when the position was created at the Insituut Kern (the Indological institute at the Univ.
[1] De Jong is well known for his amazing linguistic ability having had a command of Dutch, French, English, German, Chinese, Japanese, Russian, Danish, Mongolian, Sanskrit, Pāli, and Tibetan, as well as the rather acerbic quality of his reviews.
In April 2000, some 12,000 items from his personal library (which itself contained over 20,000 volumes) was purchased from his family in Canberra by the University of Canterbury in Christchurch, New Zealand.