After making guest appearances on various TV shows such as Bram and Alice, he eventually found fame playing "Dr. Todd 'The Todd' Quinlan," a hypersexual surgeon in friend Bill Lawrence's sitcom Scrubs. He has also guest-starred in another Lawrence production, Spin City, in 1996, and played a jury member in Veronica Mars in 2005. During the summer of 2006, he played Louis Browning, a rapist on the daytime soap As The World Turns. Louis Browning was slashed to death by a serial killer called 'the slasher'. Robert Maschio has expressed his enjoyment playing the soap opera role.