Getting the actors to play professional-looking tennis proved much more difficult than anticipated. Eventually, it was decided to film them performing the strokes and digitally add the ball afterwards.
Scenes for the film were filmed during the Wimbledon tournament 2003. The actors would walk out on court at the beginning or end of a match as though they were really competing. The officials and spectators were actual tennis officials and spectators, rather than extras. It is the only time in the history of the tournament that this has been allowed.
The movie cast professional, but little known tennis players to play against the stars. In the directors commentary, Richard Loncraine shared that he met an up-and-coming female tennis player but rejected her as she looked too similar to Kirsten Dunst. She was Maria Sharapova, before she went on to win several Grand Slam Titles, including Wimbledon.
The actors actually did their own serves with real tennis balls.
The scenes showing the public queuing outside Wimbledon were in fact shot at London Zoo, simply because it looks more interesting.