Coria turned professional in 2000, finishing 2003, 2004 and 2005 as a top ten player. He is one of the fastest players in the Association of Tennis Professionals, consistently showing great performances on clay courts tournaments and is often a major threat at the French Open.
Coria tested positive for nandrolone in April 2001 and was initially suspended two years. Coria claimed that the only supplement he was taking was a multivitamin made by an NJ supplements company. His family had a private lab test the multivitamin, which found them contaminated with steroids. Subsequently, the ATP reduced his suspension to only the seven months that had already passed. Coria sued the company for more than $10 million in lost prize money and endorsements and settled after the third day of the trial for an undisclosed amount.
At the 2004 French Open, as the favourite to win the title, he reached the final, beating former world number 1, Carlos Moyà, in the quarter finals and British serve and volleyer, Tim Henman, in the semi finals; but he was unexpectedly defeated by unseeded compatriot Gastón Gaudio in an unprecedented all-Argentine final, 0–6, 3–6, 6–4, 6–1, 8–6. Coria had won the first two sets convincingly and was in control of the third set at 4-3 up when the crowd started a Mexican wave, which galvanised Gaudio and got him to forget his nerves. Coria succumbed to leg cramps in the fourth set, at times barely able to move. But Coria played on, and he twice served for the match in the fifth set at 5-4 and 6-5, having 2 championship points in the latter game, but he missed the line by an inch both times when he attempted a winner. In the end, Gaudio prevailed in a thrilling finish.
Coria withdrew from the 2006 French Open and Wimbledon as he attempted to sort out the problems with his game, recover from a niggling elbow injury, and rediscover his old form. In August 2006 he hired Horacio de la Peña as his tennis coach. At the 2006 US Open, Coria retired in his first round match against Ryan Sweeting after just 5 games. It would be 17 months before Coria played a match on the ATP tour again.
As a result of Andy Roddick's withdrawal from the 2008 French Open due to a back injury, Coria made his first Grand Slam appearance since the 2006 US Open in taking the place of the American. He was given the unenviable task of facing Tommy Robredo, the three-time quarter-finalist and #12 seed, in the first round. Coria was defeated in four sets as Robredo won 5-7, 6-4, 6-1, 6-4, but Coria's performance led to much optimism, including from Coria himself who was close to taking the match into a fifth set.
Whether Coria ever manages to recover from the service yips that has damaged his game and kept his ranking hundreds of places below his once top 10 position, remains to be seen.