Born Robert Lee Maupin, in Chicago on August 4, 1918, he spent his childhood in Milwaukee and Rockford, Illinois until he returned to Chicago. When his mother was abandoned by his father she established a beauty shop and worked as a domestic to support both of them in Milwaukee.  In his autobiography Robert expressed gratitude that his mother didn't abandon him as well. She earned enough money working in her salon to give her son the privileges of a middle-class life like a college education, which at that time was not an option for the average person. He attended Tuskegee University, but dropped out when he found he could make money being a pimp. His mother had wanted him to be a lawyer, but Robert, seeing the pimps bringing women into his mothers beauty salon was far more attracted to the model of money and control over women that the human traffickers provided.
Robert started pimping at 18, and continued to be engaged in human trafficking until age 42, in 1960, after a final 10-month prison stretch in solitary confinement. At that point, he decided he could continue making money off trafficking by writing about it instead. Slim moved to California in the 1960s to pursue writing under the Iceberg Slim pen-name, but in normal life, changed his name to Robert Beck, taking the last name of the man his mother was married to at the time.
During his career he had over 400 women, both black and white, working for him. He was known for his frosty temperament, and and at six feet, three inches tall and 180 pounds, he was indeed slim. He also had a reputation for icy calm in sticky situations. He thus earned the street name Iceberg Slim. When verbal instruction and psychological manipulation failed to keep his women in line, he beat them with wire hangers; his autobiography makes no bones about his being a ruthless, vicious man.
In 1969, his first autobiographical novel was Pimp: The Story of My Life, published by Holloway House.
Reviews of Pimp were mixed; it was quickly categorized as being typical of the black "revolutionary" literature then being created. However, Beck's vision was considerably bleaker than most other black writers of the time. His work tended to be based on his personal experiences in the criminal underworld, and revealed a world of seemingly bottomless brutality and viciousness. His was the first insider look into the world of black pimps, to be followed by a half-dozen pimp memoirs by other writers. Of his literary contribution, a Washington Post critic claimed, "Iceberg Slim may have done for the pimp what Jean Genet did for the homosexual and thief: articulate the thoughts and feelings of someone who's been there."
Pimp sold very well, mainly among black audiences. By 1973, it had been reprinted 19 times and had sold nearly 2 million copies. Pimp was eventually translated into German, French, Italian, Portuguese, Spanish, Dutch, Swedish, Finnish and Greek. Nevertheless, the book's audience remained predominantly black.
Following Pimp, Beck wrote several more novels: Trick Baby, Naked Soul of Iceberg Slim (Los Angeles: Holloway House, 1971), Mama Black Widow, Long White Con, Airtight Willie & Me, and Death Wish: A Story of the Mafia. He sold over six million books prior to his death in 1992, making him one of the best-selling African-American writers (after Alex Haley). All his books were published exclusively aspaperbacks. Iceberg Slim also released an album of poetry called Reflections in the early 1970s.
Recordings Reflections (first press 1976, ALA Records); producer: David Drozen; executive producer: Louis Drozen; music: Red Halloway Quartet; photography: Robert Wotherspoon Reflections (reissue 1994, Infinite Zero/American Recordings/Warner Bros. Records) Reflections (reissue 2008, Uproar Entertainment) Film adaptations
In 1972 Iceberg Slim's third novel, Trick Baby, was adapted as a movie of the same name, directed by Larry Yust. The movie was produced independently for $600,000 with an unknown cast. Universal Pictures acquired the film for $1,000,000 and released it in 1973 to a considerable amount of Iceberg Slim fanfare. The movie grossed an impressive $11,000,000 at the US box office. 
As of 2011, Mama Black Widow is in active development with Marshall Tyler attached to direct from an adapted screenplay by Tyler and Will De Los Santos. Chris Hanley and Dave Mortell are producing. Mama Black Widow is Robert Beck's tragic story of a sharecropper family's migration from Mississippi to Chicago during the 1930s and is Beck's only critically acclaimed novel of his seven novels written.
A movie adaptation of Pimp has been tried for a long time. There were announcements of a movie to be directed by Bill Duke and starring Ice Cube in the early 1990s. In 2009, television executive producerRob Weiss of the HBO show Entourage, and Mitch Davis, purchased the film rights to produce Pimp.