Taking the surname of his stepfather, playwright George Tabori, the young actor received his initial training at NYC's High School for the Performing Arts, before studying with various teachers. He began his career with the Berkshire Theatre Festival in Massachusetts in 1966. Within two years, Tabori had made his NYC stage debut and frequently appeared in Shakespearean productions during the late 60s and 70s. He won acclaim for several off-Broadway performances, particularly in "The Wager" (1974-75) and "The Common Pursuit" (1986-87). The latter co-starred his future wife, British actress Judy Geeson. (They have since divorced).
On the big screen, Tabori's appearances have been sporadic and generally in small roles. His first screen appearance was in 1958's "Weddings and Babies", which starred his mother. Tabori appeared as a boy scout in "John and Mary" (1969), had a bit role in his father's "Dirty Harry" (1971) and the leading role of a sexual active teenager in John Erman's "Making It" (1971). After a small role in Claudia Weill's "Girlfriends" (1977), he did not appear in a feature until 1995's "Last Summer in the Hamptons", Henry Jaglom's Chekhovian take on a theatrical family. In a bit of inspired casting, he was the actor-director son of a grande dame, played by Viveca Lindfors in her final screen role.
Tabori's gentle demeanor has been fully exploited in the numerous appearances he has made on the small screen. A frequent guest on episodic TV (everything from "Medical Center" to "Trapper John, M.D." to "Murder, She Wrote"), he has excelled in the various miniseries and TV-movies in which he has appeared. One of his very best performances was as a terrified young man incarcerated for the first time in the gritty "Truman Capote's The Glass House" (CBS, 1972). He also offered fine turns in "QB VII" (ABC, 1974), as Ben Gazarra's son, "Black Beauty" (NBC, 1978) and on the short-lived series "Chicago Story" (NBC, 1982), as a surgeon.
Since 1990, Tabori has carved a niche as a TV director, helming various episodics as well as the occasional special geared for a younger audience. He made his bow (billed as Kristoffer Siegel-Tabori) behind the camera with an "ABC After School Special" entitled "Perfect Date". Among the many sitcoms and series to his credit are "Brooklyn Bridge", "Law & Order", "Jack's Place" and "Marker".