See main article: 2004 Swisscom Challenge.
Alicia Molik defeated Maria Sharapova in the final, 4–6, 6–2, 6–3 to win the singles tennis title at the 2004 Swisscom Challenge.
Justine Henin-Hardenne was the reigning champion, but did not compete this year.
The top four seeds received a bye into the second round.