Sen. Edward Kennedy, who is fighting a malignant brain tumor, is back at work in the Senate for the first time since July.
He met Monday with his staff as the Senate returned for a brief session to deal with the economic crisis.
The Democrat said he is looking forward to working on an economic stimulus package and is optimistic he can help forge a breakthrough on health care reform.
He is expected back at the Senate Tuesday for leadership votes and may meet later in the week with colleagues to discuss health care reform.
Kennedy had a seizure in May and underwent surgery in June. After undergoing chemotherapy and radiation, he has increased his public activity. He spent time recovering at his home in Massachusetts and returned to Washington late last month.
In July, he made a surprise return to Congress to vote on a medical care bill.
NBC's Ken Strickland contributed to this report.