Prime Minister Dr. Manmohan Singh would be undergoing coronary artery bypass graft surgery at the All India Institute of Medical Sciences (AIIMS) tomorrow.
The surgery would be performed by a team of doctors drawn from AIIMS and the Asian Heart Institute, Mumbai.
They would be supported by a team of doctors and technical staff drawn from other departments of AIIMS.
Earlier this week, Dr. Singh underwent extensive medical tests at AIIMS.
An official PMO statement on Wednesday said the Prime Minister had undergone "diagnostic evaluation" and "treatment procedures which have been recommended would be undertaken in a few days".
Dr. Singh is a diabetic and has been controlling the condition with medicines and exercise like regular walking.
Dr. Singh, 76, underwent a cardiac bypass surgery in 1990 in UK, and angioplasty in Delhi in 2004 in which stents were introduced in his arteries.
Grafts, which were used to bypass the diseased vessel on Dr. Singh 18 years ago, have once again started to narrow.