According to News.com this is the first time a member of the Spanish royal family is summoned to appear in a court of law for wrongdoing.
Cristina's husband, former Olympic handball player Inaki Urdangarin, and his former business partner Diego Torres are being investigated for a case involving embezzlement and influence peddling. The case was opened in late 2011.
The Princess, who is the seventh in line to the Spanish throne, is being accused of allowing her royal connections to be used in her husband's unlawful business dealings.
The 47-year-old daughter of King Juan Carlos will take the stand on April 27 at the court in Palma on the Mediterranean island of Mallorca.
"The royal household does not comment in any way on judicial decisions," a spokesman for the royal family said Wednesday.