In a blog post, the 70-year-old said he'll take a "leave of presence."
The veteran critic has previously battled cancer in his thyroid and salivary glands and lost the ability to speak and eat after surgery.
In a lengthy essay posted late Tuesday, Ebert says the latest cancer was discovered after a "painful fracture" that made it difficult for him to walk. The Pulitzer Prize winner was hospitalized late last year with a hip fracture.
Ebert writes he's "not going away." Instead, he'll write select movie reviews while leaving the rest of the work to a team of writers.
He also plans to spend time writing about his own health challenges.