Herbert and Donald continued until Herbert's death in 1989. Then, Donald began performing with his son, John II. In 1998 the Recording Academy recognized the Mills family's contributions to popular music when it presented Donald, as the sole surviving member, with a Grammy Award for Lifetime Achievement.

John H. Mills retired in 1956, and the brothers continued as a trio, recording and performing regularly into the 1970s. The act came to an end after Harry's death in 1982, but Donald Mills in his last years performed the group's hits with his son, John H. Mills II.

The ensemble was comprised of four brothers – John Jr., Herbert, Harry, and Donald Mills. Collectively, they became known for their innovative use of harmony and rhythm, influencing many artists across different genres and generations.

The caution was understandable, since the Mills Brothers were so proficient at re-creating trumpets, trombones, and saxophones with only their voices that early singles like "Tiger Rag" and "St. Louis Blues" sounded closer to a hot Dixieland combo than a vocal group.