Over 250,000 are expected to attend this year's Laya Healthcare City Spectacular festival in Dublin and Cork.
The festival, which is free, previously brought 14,000 people dressed as Where's Wally, 1500 more bouncing on space hoppers, a custard pie throwing championship, and a rainbow disco.
This year organisers are adding a record-breaking sword swallower, a weight-lifting strong woman, silent disco tour and rapping and science workshops for kids to the bill.
City Spectacular takes place at Dublin's Merrion Square July 10-12 and Cork's Fitzgerald Park July 18 and 19.
Growing from an original attendance of 26,000 to 240,000 it is now Ireland's second biggest festival after St Patrick's Day.
City Spectacular was previously called the Street Performance World Championship and despite the name change there's still plenty in the way of street entertainment with the return of some fan favourites - sword-swallower and blind-folded chainsaw juggler The Space Cowboy, bed of nails and fire-eating Sideshow Shep, world record-holding football freestyler Victor Rubilar and b-boy troupe US Breakdancers who have been touring with Cirque du Soleil's Michael Jackson 'One' tour.
This year the programme also includes free children's workshops in art, music, theatre and science, a family farm area, an award-winning Belgian trampoline spectacle, and an Irish food area.
All activities are free - check out the full programme at www.cityspectacular.com