After college, Hal Gurnee moved to New York in 1948 to work in advertising, having been inspired by films such as Jack Conway’s The Hucksters. This career was short-lived as he began working at the DuMont Television Network in the control room during the early age of television in the 40s and 50s. It was here he worked on one of DuMont’s most well-known shows, Jackie Gleason’s Cavalcade of Stars, as well as associate directing New York Yankees and Giants games. When the Dumont Network went out of business, Gurnee took a job as an AD at NBC, working on a variety of shows including The Tonight Show which had recently switched hosts to Jack Paar. When the director of the show was fired, Gurnee was given his big break and asked to helm the show, becoming the full-time Tonight Show director up until Paar’s run ended in 1962. Gurnee continued to direct the show during the transition period before Johnny Carson was given the reins to the show, working closely with guest hosts Merv Griffin, Groucho Marx and Jerry Lewis. Gurnee subsequently went with Paar to direct his post-Tonight Show productions of the 1960s and 70s, The Jack Paar Program and Jack Paar Tonite.
After semi-retiring from the business, a chance run-in with producer and manager Jack Rowlins led to Gurnee taking over directorial duties for the soon-to-be-cancelled daytime talk show, The David Letterman Show on NBC. This began a long personal and professional relationship with David Letterman, and when just a year after the daytime series ended and Letterman was given Late Night to follow The Tonight Show, Gurnee was hired to direct. Gurnee, along with Letterman, was instrumental in setting the show in New York instead of Los Angeles, where it remained its entire run. In 1992 when David Letterman was passed over for The Tonight Show job after Johnny Carson ended his 30-year tenure, Gurnee moved to CBS with the host to direct and produce his new, and still-running, Late Show with David Letterman, where he continued to film out of New York. Despite again semi-retiring in 1995, Gurnee returned to television to direct The Man Show in 1999.
For his directorial efforts Gurnee was nominated for nine DGA Awards; six for Late Night With David Letterman (1988-93) and three for Late Show with David Letterman (1994-96). He was also nominated for 12 Primetime Emmy Awards, all for his shows with David Letterman, winning twice, for directing Late Night in 1991, and producing Late Show in 1994.