Henin, 28, injured her right elbow during a match last year at Wimbledon and didn't play the rest of 2010. Before that, however, she was a very respectable 33-8 in matches with two tournament victories since ending a 21-month retirement in January 2010. One of the losses was in the finals of the Australian Open.
This year in Melbourne she lost a tight third-round match.
Henin posted a notice on her Web site saying she was again leaving competitive tennis.
"I turn, and this time, an incredible page of my life," she wrote. "What a wonderful trip I have experienced during all these years. Today I am calmer and I can create (a) positive and rewarding look back on this experience in my life."
Henin surprisingly walked away from the game in March 2008 when she was ranked No. 1. She was on top of the rankings for 117 weeks, the seventh highest such total. She had risen to No. 12 in her comeback last year.
Henin won 43 WTA titles, including seven major tournaments. Her match record is 527-116, an 83 percent win rate that is seventh best all-time.