Kistiakowsky came from a family of academics in Kiev, now in Ukraine. He began his education in his native city but, after fighting against the Bolsheviks, completed it in Berlin. He moved to America in 1926 working first at Princeton before moving to Harvard where he was appointed professor of chemistry in 1937, a post he retained until his retirement in 1971.

His most important work during World War II was as head of the Explosives Division at Los Alamos (1944–45). On being told of the project his initial reaction had been: “Dr Oppenheimer is mad to think this thing will make a bomb.” The basic device, proposed by Seth Neddermeyer, consisted of a thin hollow sphere of uranium that would become critical only when ‘squeezed’ together. In theory this was achieved by surrounding the subcritical uranium with conventional explosives whose detonation would compress the radioactive material into a critical mass. To work the process must take place in less than a millionth of a second and with great precision and accuracy. Right to the very end there was considerable doubt as to whether Kistiakowsky could solve the technical problems involved.

After the war Kistiakowsky, very much a figure of the scientific establishment, spent much time advising numerous governmental bodies. From 1959 until 1961 he served as special assistant for science and technology to President Eisenhower, later writing an account of this period in A Scientist at the White House (1976). Toward the end of his life he spoke out about the dangers of nuclear weapons.