Mansfield gave up his career to help his wife promote her book, Valley of the Dolls, which was published in 1966 and became the best-selling novel of the year.
Mansfield continued to work with his wife in promoting her subsequent novels, The Love Machine (1969) and Once Is Not Enough (1973), both among the top three sellers of their respective years.
Susann was impressed by his ability to place "items" about her in the theater and society pages of New York newspapers, and they were married on April 2, 1939.
In 1983, learning of an upcoming biography of Susann, Mansfield published his own book, Life with Jackie (Bantam), written with Jean Libman Block.
Editor Michael Korda gave this description of Irving Mansfield, ".. talked and acted as if he were a character straight out of Guys and Dolls, and was comfortable only at places like Lindy's, the Stage Delicatessen, and Sardi's (although late in life he managed to settle into the West Coast equivalent: a bungalow and a cabana at the Beverly Hills Hotel and a table at the Polo Lounge).