He began arranging professionally in his teens, when he wrote charts for Nat Towles. He became a prominent composer and arranger while playing trumpet for Woody Herman; while working for Herman he provided new arrangements for "Woodchopper's Ball" and "Blowin' Up a Storm," and composed "The Good Earth" and "Wild Root." After leaving Herman's band in 1946, Hefti concentrated on arranging and composing, although he occasionally led his own bands. He is especially known for his charts for Count Basie. In the 1960s and later he composed and arranged mainly for movies and television.