Born in New York City in 1921 to parents of modest means, Rosalyn Sussman Yalow grew up in a home without many books but with a strong belief in education. Her early academic drive carried her to Hunter College, where she discovered a passion for physics at a time when few women were encouraged to enter the field.

After earning her PhD at the University of Illinois, Yalow returned to New York and began working at the Bronx Veterans Administration Hospital. There she formed a long‑standing research partnership with physician Solomon Berson. Together, they developed radioimmunoassay (RIA), a groundbreaking technique that allowed scientists to measure tiny concentrations of hormones and other substances in the blood with unprecedented precision. This innovation revolutionised endocrinology, diagnostics, and medical research worldwide.

Yalow’s achievements earned her numerous honours, culminating in the 1977 Nobel Prize in Physiology or Medicine, which she shared with Roger Guillemin and Andrew Schally for their complementary work on peptide hormones. Despite her acclaim, she remained deeply committed to her laboratory and to mentoring younger scientists. She continued her research at the Bronx VA until 1991, demonstrating the same tenacity that had defined her since childhood.

She died in New York in 2011 at the age of 89, leaving behind a scientific legacy that continues to influence medicine today.