Capriati was introduced to tennis while she still a toddler by her father, Stefano Capriati, an Italian-American former boxer turned tennis coach, who has continued to coach her in her later professional career.

In 1986, when Jennifer's burgeoning tennis talent became obvious, her family moved to Florida, where the ten-year-old player was enrolled in an intense training program run by Jimmy Evert, the father of Chris Evert.

In 1989, Capriati served notice to the tennis world by becoming the youngest player to win the French Open junior singles title at the age of 13 years and 2 months. (The record stood until 1993, when it was broken by Martina Hingis who won the title as a 12-year-old). Capriati went on to win the junior singles title at the 1989 US Open, and the junior doubles titles at both the US Open and Wimbledon (partnering Meredith McGrath).

Capriati turned professional on March 5 1990, three weeks before her 14th birthday. In her debut tournament on the tour, at Boca Raton, Florida, she defeated four seeded players on her way to becoming the youngest-ever player to reach a tour final, where she lost 6-4, 7-5 to Gabriela Sabatini.

Three months later, she became the youngest-ever semi-finalist at the French Open (aged 14 years and 2 months), where she lost to the eventual champion Monica Seles. Capriati went on to reach the fourth round at both Wimbledon and the US Open that year, and won her first top-level singles title that October at San Juan, Puerto Rico. She finished her first year on the tour ranked the World No. 8.

1991 saw Capriati reach the semi-finals at Wimbledon and the US Open. She became Wimbledon's youngest-ever semi-finalist after defeating the defending-champion Martina Navratilova in the quarter-finals, forcing Navratilova's earliest Wimbledon exit for 14 years. She won two singles titles that year, as well as her first (and only) tour doubles title (in Rome partnering Monica Seles).

The biggest moment of Capriati's early-career came in 1992, when she won the women's singles Gold Medal at the Olympic Games in Barcelona. In the final, she defeated Steffi Graf (who was the Gold Medalist four years earlier in Seoul) in three sets 3-6, 6-3, 6-4.

But despite her Olympic triumph, it became clear to observers that Capriati was struggling to cope with the pressures of playing at the top by the end of 1992. The enjoyment of playing the game which she exuded when she first joined the tour seemed to have drained away, and her results started to suffer.

After some disappointing losses in 1993, Capriati took a break from the tour to concentrate on her high school studies. She soon ran into personal and legal troubles. She was involved in a shoplifting incident in December 1993, and in May 1994, she was arrested for marijuana possession. In November 1994, a return to the tour lasted just one match, which she lost. After that, she went on a sabbatical of 15 months and did not play on the tour for the whole of 1995.

Returning to the tour in 1996, Capriati again had several false starts. In May 1999, she finally won her first tournament in six years at Strasbourg.

In 2001, 11 years after she had first taken the tour by storm as a young prodigy, Capriati finally made her Grand Slam breakthrough. She reached the final of the Australian Open against the then-World No. 1 player Martina Hingis, and won in straight sets 6-4, 6-3. She followed this up by capturing the French Open title five months later, beating Kim Clijsters in a dramatic final 1-6, 6-4, 12-10. In October 2001, Capriati reached the World No. 1 ranking.

Capriati won her third Grand Slam title in 2002, when she successfully defended her Australian Open crown. In the final against Hingis, Capriati was 4-6, 0-4 down at one point, but battled back to win 4-6, 7-6, 6-2. She fought off 4 Championship points during the final, which is a record for most match points saved during a Grand Slam tournament final.

In 2003, Capriati made an inspiring run to the U.S. Open semi-finals, only to lose a classic match to Belgium's Justine Henin-Hardenne in a third set tiebreak, with the final score 6-4, 5-7, 6-7(4). The battle concluded well past midnight, and left Henin-Hardenne needing medical attention due to dehydration and exhaustion. During the match, Capriati was just two points from victory a remarkable eleven times.

During her career, Capriati has won 14 professional singles titles and 1 doubles title. Recently, she has suffered several dramatic defeats and has struggled with various injuries that have kept her from playing a full tour schedule.