Her spokeswoman, Sally Morrison, said Friday that the Oscar-winning actress was admitted to Cedars-Sinai Medical Center within the past couple of days.
The 78-year-old Taylor is being treated for symptoms caused by congestive heart failure, a condition she disclosed she had back in November 2004.
Morrison said it's unknown how long she might be in the hospital. She added that Taylor's family appreciated the support from fans, but asked for privacy to allow the medical team space to do its work.
Taylor had been scheduled to attend an amfAR benefit gala Wednesday night in New York, where she was to receive an award alongside President Bill Clinton and designer Diane von Furstenberg, celebrating their dedication to AIDS research.
But she missed the event, so Elton John accepted the honor on her behalf and passed along a message from her: "I am there in spirit and I join you in saluting my fellow honorees and all these extraordinary leaders. I am inspired by their example, exhilarated by their vision, and encouraged by their compassion and love. And I love them in return."
Taylor, who's appeared in more than 50 films, won Oscars for her performances in "Butterfield 8" (1960) and "Who's Afraid of Virginia Woolf?" (1966). But she's been just as famous for her marriages - all eight of them, including two to Richard Burton - and her lifelong battles with substance abuse, her weight and physical ailments, including numerous visits to the hospital for more than 20 major operations and countless treatments.
The actress had near-fatal bouts with pneumonia in 1961 and 1990, and another respiratory infection forced her to cancel all engagements for several weeks in late 1992. She had both hip joints replaced in 1994 and 1995.
Her 2004 diagnosis for congestive heart failure, compounded with spinal fractures and the effects of scoliosis, left her nearly bedridden. She's also battled ulcers, amoebic dysentery, bursitis, and had a benign brain tumor removed in 1997. In recent years, she has had to use a wheelchair when out in public.