Gibson began regularly anchoring ABC World News Tonight after long-time anchor Peter Jennings’ treatment for lung cancer forced him off the set in April 2005. On August 7, 2005, Gibson announced Peter Jennings death and the following day anchored the first World News Tonight following Jennings' death. He was a leading choice to replace Jennings and was eventually offered the job. However, Gibson couldn't agree with ABC News president David Westin over how long he would stay in the chair ^*. Elizabeth Vargas and Bob Woodruff were then chosen to be Jennings' permanent replacements on December 05, 2005.

Woodruff's severe injury in Iraq on January 29, 2006 suddenly threw the new World News Tonight anchor arrangement into confusion. There were doubts Vargas could sustain the program on her own over the longterm. Ratings were slipping. In March 2006, The New York Post's Cindy Adams reported that Charles Gibson will become Bob Woodruff's "Temporary Permanent Replacement" on WNT. On May 23 2006, Gibson was named sole anchor of WNT, effective May 29, 2006, after Vargas announced her resignation from the show; she cited her doctors' recommendation to cut back her schedule considerably due to her upcoming maternity leave, and her wish to spend more time with her new baby. [http://www.abcnews.go.com/WNT/story?id=1993658&page=1