In 1977, Kimball joined a group of fellow Los Angeles session musicians called Toto by submitting a self-penned audition song for the band, "You are the Flower," which was included on their debut album. He recorded the first four studio albums for Toto, before drug and personal issues began to cause conflicts among the other members of the band. He was released from the band in 1984 during sessions for Isolation, their follow-up studio album to 1982's Grammy Award-winning Toto IV.