Cheech (r) and Chong played bumbling 'stoners' in their films
Comedy duo Cheech and Chong, who made a series of films and albums in the 1970s and 80s, are set to tour again more than 20 years after they split.
The pair, whose routines were based on the hippie era and its associated free love and drug culture, will kick off the Light Up America tour in September.
The US comedians said they decided to reform because neither of them "are getting any younger".
Cheech, 62, and Chong, 70, won a Grammy award for best comedy album in 1973.
They starred in eight comedy films, invariably playing a pair of bumbling "potheads".
The pair, who split in 1987 due to creative differences, told reporters in Los Angeles that they had "kind of resolved" their "veiled hatred".
They decided that reuniting for a comedy tour would be "the most fun" and "the least hassle".
After their split, the two comedians embarked on solo careers, with Cheech Marin performing voice work for a number of films including The Lion King.
Tommy Chong became best known for playing drug-addled hippie Leo in sitcom That 70s Show.
In 2003 he was jailed for nine months for selling drug paraphernalia over the internet.
During the trial he admitted to having a marijuana problem.