His big break came in 1997 when he won 536 races made him the fourth rider in history to win 500 races in one year. Much of that success was gained in Maryland, where he ruled that circuit for several years.
A resident of Hollywood, Florida in 2004 Prado became the 19th jockey in thoroughbred racing history to win 5,000 races. Edgar has three children named Edgar Jr, Louis and Patricia.
On May 6, 2006, Prado rode Barbaro to victory in the 132nd Kentucky Derby, 6½ lengths ahead of the second finisher, Bluegrass Cat. The margin of victory was the largest since Triple Crown winner Assault won by eight lengths in 1946. Barbaro was pulled up following a horrific ankle injury during the Preakness Stakes two weeks later. Prado was visibly shaken, declining comment, but by all accounts his fast action on the track contributed to saving the colt's life. (However, Barbaro was euthanized by veterinarians at the University of Pennsylvania's New Bolton Center on January 29, 2007.)
Other racing accomplishments include victories in the 2002 and 2004 Belmont Stakes, in each case aboard a longshot depriving a favorite of the United States Triple Crown. In 2002 Prado won the Belmont aboard Sarava, who is the longest shot to ever win the Belmont Stakes in its history at odds of 70¼/1. In 2004 Prado rode Birdstone to victory in the Belmont, denying heavy favorite Smarty Jones the Triple Crown. Prado and Birdstone then went on to win the prestigious Travers Stakes at the Saratoga Race Course in Saratoga Springs, New York in August 2004.
On September 24, 2006, Prado received the New York Racing Association's 2006 Mike Venezia Memorial Award in a paddock ceremony at Belmont Park. The winner of this award is decided by the votes of fellow jockeys, turf writers and an online vote by fans. It honours those "...who exemplify extraordinary sportsmanship and citizenship", and is given in memory of Mike Venezia, killed on October 13, 1988 in a spill at Belmont Park. On February 10, 2008 at Gulfstream Park, Edgar Prado achieved his 6000th win. Only 16 jockeys in the United States have achieved this record.
Prado is involved with Belmont Park's "Anna House", a child day care centre providing care for the children of backstretch workers.
On August 4, 2008 he was formally inducted into the National Museum of Racing Hall of Fame.