Mayor Michael Bloomberg marched with labor leader Dennis Rivera, head of the Service Employees International Union and the parade's grand marshal.
Other elected officials marching included New York Gov. David Paterson, New Jersey Gov. Jon Corzine, U.S. Sen. Charles Schumer and a delegation of mayors of Puerto Rican cities.
Rep. Nydia Velazquez, the first Puerto Rican woman elected to Congress, said the parade demonstrates "the growing influence of Puerto Ricans in the city and in the nation."
The parade went up Fifth Avenue from 44th to 86th street. There were marching bands, beauty queens in foot-high tiaras and dancers in ruffled skirts.
A pair of salsa dancers maneuvered on stilts, while a Carnival performer in a horned vejigante mask and clown-like costume tried to beat the 90-plus heat by pouring water on herself.
Music blared from every float, not quite drowning out the spectators who blew whistles and shouted "Viva Puerto Rico!"
The crowds lining the avenue 10 deep waved the Puerto Rican flag and wore it on their clothes. The flag with its one star appeared on bikini tops, shirts, hats, parasols and capes worn Superman style.
Jose Batista chose not to get his hair dyed in the flag's colors this year, as he did last year. But he was wearing the flag in a dozen places including earrings, a hat, a necklace, a backpack and the lenses of his glasses. The flag was also painted on each cheekbone.
"I come every year," said Batista, of the Bronx. "I love this parade."
Although it was impossible to estimate the crowd, hundreds of thousands have attended in recent years.
Puerto Ricans are the largest Hispanic group in the city, with Census estimates putting the size of the community at about 770,000.
