Rusedski, who was born to a British mother and a German-Canadian father of Polish-Ukrainian descent, decided to adopt British citizenship in 1995. His best tournament results were reaching the final of the US Open (tennis) in 1997 where he lost to Pat Rafter (shortly thereafter reaching his career high rank of World No. 4), and winning the Grand Slam Cup in 1999. He held the record for the fastest recorded serve at 149 mph (239.7 km/h) although this has since been beaten by Andy Roddick. Overall Rusedski has won more singles titles than compatriot Tim Henman with 15 singles titles compared to Henman's 11, however, according to life long Henman fan and unofficial Henman biographer Peter Butler, his grand slam record is less impressive, having never made it passed the fourth round of the French or Australian Open.

Despite Rusedski's on-court successes and being Britain's number two tennis player (Tim Henman was number one), he was never, at first, regarded as a popular player in the hearts and minds of British fans. However his continuing participation in the Davis Cup, most notably his single handed win over Israel, and his heroic comeback from the near tennis wilderness, has led him to become more popular in recent months, and emerge from the shadow of Henman.

However his career has included some controversies. In the 1999 US Open, Rusedski's temper caused him to squander a lead against Todd Martin and lose the fourth round match; notable about that match was Rusedski losing 14-plus consecutive points during the fifth set. Rusedski had made derogatory comments about Henman after a loss to his fellow Briton during the 2002 season. In the US Open of that year, after being dispatched by Pete Sampras in the fourth round after a gruelling 5-set match, Rusedski made unsportsmanlike comments, calling Sampras "a half-step slow", and predicted that Sampras would lose his quarter-final to young German star Tommy Haas. Sampras however went on to win the tournament. In the 2003 Wimbledon, during the second round, Rusedski swore at the umpire after not being allowed to replay a point after fan interference, losing his temper and ultimately losing the match to Andy Roddick 7-6 7-6 7-5.

Greg Rusedski has been plagued by injuries in recent seasons. He tested positive for nandrolone in January 2004, but was cleared of the charges in a hearing on 10 March 2004.

In 1997, Greg won the BBC Sports Personality of the Year Award. However, his career has never reached such heights again and the next year fellow Briton Tim Henman eclipsed Rusedski as Britain's number one tennis player in both ranking and popularity.

Rusedski was defeated in the second round of Wimbledon 2005 by Joachim Johansson of Sweden 6-7 (10-12) 6-3 4-6 6-7 (7-5).

Following the disappointment at Wimbledon, Rusedski went on the have a successful few weeks in July 2005. First he defended his title at the Hall of Fame Championship in Newport, Rhode Island, beating Vince Spadea in the final. This was a great win for Rusedski as it was the first time he successfully defended a title and the third time he had won the championships; his first win there in 1993 was his first ever tour title. He then went on to reach the semi-finals at both the RCA Championships in Indianapolis, being beaten by Taylor Dent, and the Canada Masters Series Tournament in Montreal, losing to Andre Agassi.

Towards the end of the season in 2005, Rusedski had risen back up to a ranking in the high thirties. A poor end to the season by Tim Henman meant Rusedski had almost played well enough throughout the season to overtake him as British number one again. But a defeat for Rusedski in the first round of the Challenger Event in Dnepropetrovsk, Ukraine, left him ranked 38th, just one place short of regaining the British top spot.