He was moved to the Bunga Raya ward at the National Heart Institute (IJN) as doctors were happy with his progress so far.
A statement from the hospital said Dr Mahathir, 82, was able to walk unaided and was on a normal diet.
The IJN, however, is still limiting his visitors to immediate family members to reduce the risk of post-operative infection.
"From now on it will be total rehabilitation," she told the New Straits Times.
"He is a very determined person who wants to recover fast," she said, adding that IJN’s Dietetics and Food Services senior manager Mary Easaw-John was taking charge of Dr Mahathir’s diet.