In the 70s, Arledge branched out into producing primetime variety programming, starting with "Frank Sinatra--The Main Event" in 1974. He served as executive producer of the short-lived (1975-76) series "Saturday Night Live With Howard Cosell" as well as the biannual "Battle of the Network Stars". In 1977, to the consternation of critics who questioned his lack of journalistic experience, Arledge was appointed as president of ABC News (while retaining his position as head of the sports division). Despite a reputation for spending lots of money for talent, he eventually forged several successful franchises. Arledge is generally credited with the idea of having four anchors in separate cities for the nightly "World News Tonight" broadcast--an experiment which lasted for nearly five years when it was abandoned in favor a single anchor (Peter Jennings). Arledge also pioneered the primetime newsmagazine with the introduction of "20/20" in 1978. While a ratings and critical disaster at first, the show later proved to be one of the network's most popular and spawned a sister show "Prime Time Live" (As of fall 1998, though, the shows were collapsed under the "20/20" umbrella.) After the 1979 Iran hostage crisis, during which Ted Koppell anchored a nightly recap in late-night markets, the network executive debuted "Nightline". Arledge is also credited with launching the Sunday morning series "This Week With David Brinkley" in 1981 (which became "This Week With Sam Donaldson and Cokie Roberts" after Brinkley's retirement in 1996). He wooed correspondents like Diane Sawyer to ABC and was largely credited - or blamed - for making newscasters rich stars on a par with Hollywood royalty.

When ABC was sold to Capital Cities in 1985, Arledge's extravagant hands-off management style was called into question. Rumors swirled that he would be replaced, but he persevered. He was forced to relinquish control over ABC Sports, however, resulting in a deterioration of quality. After weathering that upheaval, Arledge faced similar problems when Capital Cities sold the network to Disney in 1995. Soon thereafter, ABC News suffered a number of setbacks. Ratings for the nightly "World News Tonight With Peter Jennings" slipped. "Good Morning America" was running second to NBC's "Today" show. Several lawsuits had resulted in judgments against the news division, including a $10 million jury award to a Florida banker who claimed libel. Arledge nevertheless seemed unable or unwilling to consider a successor until 1997 when he was promoted to chairman of ABC News and David Westin was installed as president. Within a year, Arledge's post of chairman became largely ceremonial when he announced he would relinquish the day-to-day operations to Westin. When David Westin took over in 1998, ABC News had slipped to No. 2 and was faced with tough budget decisions.