The event is the fifth year of Wild in the Streets commemorating the international day of skateboarding.
The youngsters start in Barrio Aranjuez about 9 a.m. on the north side of the city and travel through Parque Morazán and Plaza Gonzales Víquez.
Youngsters come from all over the Central Valley to participate. Some are expected to come from the Pacific coast town of Playas del Coco.
At Parque de la Paz there are contests, demonstrations and prizes.
The event has official recognition form 11 municipalities. The sponsor is the Red Bull energy drink.
The youngsters always seem to be on their best behavior, and one of the final projects Sunday is to clean up any trash.