[2] He began his PR practice from his parents' kitchen and it grew to become the most influential public relations organization in New York City.

Rubenstein grew up in a Jewish-American[3] household in Bensonhurst, Brooklyn, on 74th Street near Bay Parkway with an elder sister, June.

His mother, Ada, an immigrant from Russia from age nine, was a homemaker, and his father, Sam,[4] was a crime reporter for the New York Herald Tribune.

He graduated from Midwood High School in Brooklyn,[5] and then from the University of Pennsylvania Phi Beta Kappa in 1953 with a degree in economics.

After graduating from law school in 1959, he took a job as an assistant counsel to the United States House Committee on the Judiciary, but quit after six months.