While his parents (actor-director John Astin and award-winning actress Patty Duke) pointed out the pitfalls of a show business career, handsome Mackenzie Astin nevertheless chose to act while still a youngster. Like his mother, he was able to make the transition from child player to adult performer after taking a short break to briefly attend college. Astin made his performing debut at age eight in the CBS TV-movie "Lois Gibbs and the Love Canal" in 1982. Three years later, he made a guest appearance on his mother's short-lived ABC sitcom "Hail to the Chief" before joining the cast of the NBC sitcom "The Facts of Life" as wayward youth Andy Moffett. While a popular figure among the Tiger Beat set, the actor segued to the big screen in the crude comedy "The Garbage Pail Kids Movie" (1987). After three seasons and a handful of other TV appearances, Astin took a break to complete high school and enroll at his father's alma mater Johns Hopkins University.
The allure of acting proved too strong, however, and Astin dropped out of college to resume his career, appearing as Beverly D'Angelo's son in the based-on-fact drama "A Child Lost Forever" (NBC, 1992). He returned to features in the leading role of "Iron Will" (1994), a plucky early 20th Century teenager who enters a dogsled race to rescue his family from financial ruin. He later was featured as the aimless, teenaged father grandson of the overbearing Aurora Greenway (Shirley MacLaine) in the uneven "The Evening Star" (1996), a sequel of sorts to James L Brooks' superior "Terms of Endearment" (1984). Astin received some praise for his portrayal of Henry S. Villard, friend and romantic rival to Ernest Hemingway, in Richard Attenborough's overblown and empty romantic drama "In Love and War" (also 1996). In another based-on-fact tale, he played the victim of a violent shooting on a commuter train in the well-received 1998 NBC TV-movie "The Long Island Incident". Astin also contributed strongly to the ensemble of Whit Stillman's feature examination of early 80s night life "The Last Days of Disco" (1998).