Hingis won last week's Betty Barclay Cup in Hamburg, Germany, rolling over Arantxa Sanchez-Vicario of Spain in the final, and recaptured her No. 1 ranking from American Lindsay Davenport in the process. It was the fourth title of the year for Hingis, who has a 10-match winning streak.
The 19-year-old Hingis, who received a first-round bye as one of the top eight seeds, defeated Julie Halard-Decugis of France here in last year's final.
Hingis faces a depleted field this week. Davenport is not entered and U.S. Open champion Serena Williams of the United States withdrew with a left knee injury.
Second seed Nathalie Tauziat of France will make her claycourt debut this week. She has lost four of her last six matches since winning the Open Gaz de France at Paris in February.
Spain's Conchita Martinez, the third seed, won this title two years. Although she has reached two finals this season, she is looking for her first title of the year. Martinez is 10-4 on clay this season, having reached the quarterfinals last week in Hamburg.
Halard-Decugis is the fourth seed, followed by Sandrine Testud of France, Sanchez-Vicario, Anna Kournikova of Russia, and Anke Huber of Germany.
In today's first round, No. 13 Ruxandra Dragomir of Romania plays Sarah Pitkowski of France and 16th-seeeded Patty Schnyder of Switzerland meets Rita Kuti Kis of Hungary.
Also today, Sylvia Plischke of Austria faces Martina Muller of Germany, Austria's Anne Kremer battles Croatia's Mirjana Lucic, Elena Dementieva of Russia encounters Cara Black of Zimbabwe, Emmanuelle Gagliardi of Switzerland goes against Anna Smashnova of Israel, Alexandra Stevenson of the United States takes on Tatiana Panova of Russia, and Argentina's Paola Suarez squares off against Spain's Nuria Llagostera.
The $1.08 million claycourt event offers a first prize of $166,900.