[4] After his discharge from the army in 1945,[4] Davis went to work at Monsanto's Mound Laboratory, in Miamisburg, Ohio, doing applied radiochemistry of interest to the United States Atomic Energy Commission.

In 1948, he joined Brookhaven National Laboratory, which was attempting to find peaceful uses for nuclear power.

[3] Davis reports that he was asked "to find something interesting to work on," and dedicated his career to the study of neutrinos, particles which had been predicted to explain the process of beta decay, but whose separate existence had not been confirmed.

[3][2] Davis shared the Nobel Prize in Physics in 2002 with Japanese physicist Masatoshi Koshiba and Italian Riccardo Giacconi for pioneering contributions to astrophysics, Davis was recognized for his work on the detection of cosmic neutrinos,[5] looking at the solar neutrino problem in the Homestake Experiment.

Davis met his wife Anna Torrey at Brookhaven and together they built a 21-foot wooden sailboat, the Halcyon.