He was the son of Caroline Lee Bouvier Canfield and Polish aristocrat and diplomat Prince Stanisław Radziwiłł, and a nephew of former First Lady Jacqueline Kennedy.
His maternal first cousin once removed was Mary Lee Ryan (1931–2017), the wife of William Amherst Vanderbilt Cecil, owner of Biltmore.
[2] He married a former ABC colleague, Emmy Award–winning journalist Carole DiFalco, on 27 August 1994 on Long Island, New York.
[4] His work was nominated for two Emmy's: Outstanding non-fiction special for Lenny Bruce: Swear To Tell The Truth in 1999[5] and Outstanding achievement in non-fiction programming for Cancer: Evolution to Revolution in 2000[6] Around 1989 he was diagnosed with testicular cancer and underwent treatment which left him sterile but in apparent remission.
Radziwiłł battled metastasizing cancer throughout his five years of marriage, with his wife, Carole, serving as his primary caretaker through a succession of oncologists, hospitals, operations, and experimental treatments.