The fourth incarnation of the Tonight Show franchise debuted on May 25, 1992, three days after Johnny Carson's retirement as host of the program.

The series, which followed the same basic format as that of its predecessors (an opening monologue followed by comedy routines, interviews and performances), ran until May 29, 2009, after which Leno was succeeded by Conan O'Brien.

[5][6][7] Neither O'Brien's version of the program, which premiered June 1, 2009, nor The Jay Leno Show generated the ratings NBC had expected.

David Letterman wanted to move into the earlier time slot from his late night spot after The Tonight Show, and he was also considered by many as the natural successor (despite Leno having been Carson's permanent guest host for several years).

[8] With his heart set on the earlier time slot, Letterman left NBC in June 1993 and joined CBS that August.

On September 27, 2004, the 50th anniversary of The Tonight Show's debut, NBC announced Leno would be succeeded by O'Brien, in 2009.

Leno explained he did not want to see a repeat of the hard feelings and controversy that occurred when he was given the show over Letterman following Carson's retirement.

[9][10] It was announced on July 21, 2008, that Leno would host his final episode of The Tonight Show on Friday, May 29, 2009, with O'Brien and James Taylor as his guests.

On December 9, 2008, it was announced Leno would be hosting a new nightly show in September 2009, which aired at 10 pm ET, during the network's prime time period.

On July 1, 2010, Variety reported that only six months into its second life, Leno's Tonight Show posted its lowest ratings since 1992.

However, by August 2012, the Los Angeles Times was reporting that The Tonight Show was in serious trouble for a number of reasons, most notably that NBC was losing money.

[26] By March 2013, there were rumors that NBC would have Jimmy Fallon, who had been hosting Late Night since 2009 when he succeeded O'Brien, become the next host of The Tonight Show when Leno's current contract ended in 2014 and NBC would move the show back to New York for the first time in over 40 years.

[34] With 45 weeks of annual production, that amounted to about $76.5 million, excluding the salaries for Leno and the show's "top producers".

The second segment is a full comedy sketch, such as a mini-documentary by a "Tonight Show correspondent" (e.g., Ross the Intern or Mikey Day), or a trademark of Leno's, such as Headlines.

These skits often involved slapstick injury to Hall (by using a stunt double, dummy, or film clip), such as vehicles running him over in the studio parking lot.

Hall was controversially replaced in 2004 by The Howard Stern Show staff member John Melendez in what many perceived as a thinly veiled attempt to attract a younger demographic and nonsensical considering his "stuttering" moniker.

[55] In a negative review, Robert Bianco of USA Today wrote; "Monday's opening monologue, supposedly Leno's strong suit, was tired, lame and unfunny.

"[56] The show was nominated for an Emmy Award in the Outstanding Variety, Music or Comedy Series category ten times between 1993 and 2005.

[60] For at least six weeks following his return to The Tonight Show, Leno's program beat Letterman in the overall ratings each night, though with a reduced lead in comparison to his first tenure.

[61] In September 2010, The Tonight Show posted its lowest numbers on record,[62] with Leno averaging 3.8 million viewers.

Both of Leno's lead-in, Late Night with Jimmy Fallon and Last Call with Carson Daly, also received increased viewership.

From 2011 the show was broadcast on Record News with Brazilian Portuguese subtitles at midnight (local time), two days after airing in United States.

For many years, The Tonight Show episodes from the week ran back-to-back on Saturday and Sunday on CNBC Asia, available to Brunei, China, Hong Kong, Indonesia, Malaysia, Singapore and Thailand – but since October 2011, they have been replaced by Late Night with Jimmy Fallon.

In Finland, The Tonight Show with Jay Leno was broadcast by MTV3 MAX from Monday to Friday with a three-night delay.

Since 2000, the show is broadcast in the Israeli satellite company yes (which launched in that year) in various channels, the current being yes stars comedy.

In Sweden, Kanal 5 started airing The Tonight Show every night Monday to Friday with a one-week delay in 2000.