Improsaurus was formed by a group of University of Otago students in 2009 and has gained a cult following, performing at the Fortune Theatre since 2011.
Group member Jerome Cousins said until now the group had not taken its long form of improv comedy overseas, but this was about to change after it was accepted into the American Association of Community Theatre (AACT) World Festival being held in Venice, Florida, between June 16 and 21.
''We applied about eight months ago, thinking we might as well see what happens.
''We sent them a video, they loved what we do and so they invited us over,'' Mr Cousins said.
Seventeen countries will be represented at the festival, with acts ranging from Russian puppetry to Chinese opera.
The group has built up a solid audience at its shows at the Fortune Theatre.
The brand of ''long-form improv'' they practise differs from the typical improv, which involved short scenes, like the show Whose Line Is It Anyway?.
''We devise our 90-minute plays completely made up on the spot, based on the audience's suggestions.''
Fellow group member Trubie-Dylan Smith said this made every show a surprise for both audience and actors.
''It's always going to be funny, because the audience knows that we are just making it up on the spot.''
Dianne Pulham said the group all took it seriously.
''If you play it serious, the comedy comes through the truth,'' she said.
''Real life is funny.''
The group's next show at the Fortune Theatre was on Friday night.
Five of the 11 members of Improsaurus are going to the festival in Florida.