Fratello was head coach of the Memphis Grizzlies from December 2004 to December 2006. In his first season he inherited a 5–11 team that he turned around to win 45 games and advance to the playoffs. Fratello built on that record the following year to win 49 games and return to the playoffs for a second consecutive season. Before departing in December 2006, his record was 6–24 taking his overall record with Memphis to 95–87.

Prior to working with the Grizzlies, Fratello had coached the Cleveland Cavaliers and the Atlanta Hawks. In his six seasons with the Cleveland Cavaliers his record was 248 wins and 212 losses. Fratello took the Cavaliers to the playoffs four times. Fratello coached the Hawks for seven seasons and posted a 324–250 record, making the post-season playoffs five times and winning the Central Division in 1987 with 57 wins. Fratello was named coach of the year for the 1985–1986 NBA season. His NBA career stats are 666 wins and 542 losses for a .551 average. His teams have qualified for the playoffs in eleven of his 16 seasons as a head coach.

One of the most respected basketball minds despite having never won an NBA championship as a head coach, Fratello ranks 19 on the NBA's all-time win list and 21 in games coached.