Nicole Richie has been admitted to the hospital.

"Nicole has checked into Cedars-Sinai, where she is being treated for pneumonia," a rep for the star, 28, told Usmagazine.com Wednesday.

Continued the rep, "She is doing well."

Richie was too sick to attend the Nov. 10 launch of her House of Harlow jewelry line at Bebe in Los Angeles.

She and beau Joel Madden are parents to two-month-old son, Sparrow, and daughter Harlow, 22 months.