Ganguly said he would be retiring from the game at the end of the India-Australia Test series, which begins in Bangalore on Thursday.
After being controversially included for the four-Test series, Ganguly revealed that even he was surprised at his inclusion, but added that the stress forced him to take a decision on his career.
"I have decided to quit. This will be my last Test series," Ganguly told reporters in Bangalore on Tuesday.
"I have informed my team of my decision. I hope I'll end my career with a winning knock," added the 36-year-old.