Former President Mwai Kibaki is scheduled for surgery on Thursday at the Netcare Sunninghill Hospital in South Africa.
The surgery will involve removing a blood clot in a vein on his neck.
Kibaki, 84, was flown to South Africa for specialised treatment on Sunday after he spent a night at the Karen Hospital in Nairobi.
Doctors at the Johannesburg based hospital where he is admitted located the blood clot in good time while it was in a safe part of his body.
Sources close to the family say he is in a much better condition than he was when he was flown out of the country.
Details about Kibaki’s health however remain scanty as government officials and the family treated the issue with utmost privacy.
Sunninghill Hospital specialises in cardiology, a branch of medicine that deals with diseases and heart abnormalities.