Perey received a grant to study at Paris Sorbonne, but because she didnt have a bachelor's degree, the Sorbonne required her to take courses and obtain the equivalent of a B.S. to fulfill their PhD program requirements before she could earn her doctorate. She graduated from the Sorbonne in 1946 with a Doctorate of Physics. After obtaining her PhD, Perey returned to the Radium Institute as a senior scientist and worked there until 1949.
Perey was made the head of the department of nuclear chemistry at the University of Strasbourg in 1949, where she developed the university's radiochemistry and nuclear chemistry program and continued her work on francium. She founded a laboratory that in 1958 became the Laboratory of Nuclear Chemistry in the Center for Nuclear Research, for which she served as director. She also served as a member of the Atomic Weights Commission from 1950 to 1963.
Because of her work with francium, Perey was nominated five times for a Nobel Prize, but she never received it.
Ironically, Perey hoped that francium would help diagnose cancer, but in fact it itself was carcinogenic, and Perey developed bone cancer which eventually killed her. Perey died on 13 May 1975 (age 65). She is credited with championing better safety measures for scientists working with radiation.