The court had said last week that Rehnquist would be on the bench Monday, but in a statement, Rehnquist said, "According to my doctors, my plan to return to the office today was too optimistic."
Rehnquist revealed for the first time he is "continuing to take radiation and chemotherapy treatments on an outpatient basis."
He was hospitalized last week as doctors checked on the aftermath of a tracheotomy, a hole cut into the chief justice's windpipe to ease his breathing, which had become difficult during his treatment.
He returned home last Friday.
"While I am home, I am working on court matters," Rehnquist said, "including opinions for cases already argued. I am, and will continue to be, in close contact with my colleagues, my law clerks and members of the Supreme Court staff."