[1][2] Entratter was born to a Jewish family,[3][4] and began working in the French Casino in Miami as a reservation clerk[5] as a teenager.

[10] Entratter became general manager of the Sands Hotel and Casino in Las Vegas when it opened in December 1952.

[8] Entratter made many show business friends during his time as a manager at the Copacabana, where he gained renown for his smoothness in dealing with its performers and patrons.

[12] Entratter's personally selected "Copa Girls" wore $12,000 worth of costumes on the hotel's opening night (equivalent to $142,000 in 2024).

[5] Due to Mob involvement in the development of Las Vegas, Entratter was associated with mobsters such as Meyer Lansky and Hyman Abrams in the financing of the Sands,[13] which he ran with Carl Cohen, who was its entertainment director and vice president.

[18] He was described as being a large man of 6 feet 4 inches (1.93 m) in height and 240 pounds (110 kg) in weight,[6] with a "deep, baritone voice".