The 13th-ranked Belgian announced the decision on her website Wednesday, saying that her right elbow sustained additional damage while she was in Australia this month. Five days ago, she lost in the third round at the Australian Open to Russian Svetlana Kuznetsova.
Henin, a seven-time Grand Slam winner, was ranked number-one when she abruptly announced her first retirement in 2008. She returned just 20 months later and reached last year's Australian Open final.
Now 28, Henin partially tore a ligament in her right elbow in a fall at Wimbledon last June and has struggled to regain her previous form.
She was scheduled to face the United States in a Fed Cup match alongside compatriot Kim Clijsters next week in Antwerp, Belgium.
Some information for this report was provided by AP, AFP and Reuters.