25-year old Kasab was hanged at 7.30 am, Maharashtra Home Minister R R Patil said in Mumbai shortly after the hanging.
Pakistan government was kept informed about the execution.
The execution in the Mumbai attack trial brought closure to many in the audacious strike by 10 terrorists of Pakistan-based terror outfit Lashkar-e-Taiba (LeT) in which 166 people were killed. Nine LeT men were killed during the 60-hour siege which began on the night of November 26, 2008.
The prison authorities remained tight-lipped about the details of hanging performed in a well-guarded secret operation amid reports that Kasab did not have any death wish.
Kasab was executed after he exhausted all legal remedies available to escape the noose with President Pranab Mukherjee rejecting his mercy plea following the advice of the Union Home Ministry.
Maharashtra Chief Minister Prithviraj Chavan said Kasab was moved to Yeravada jail on November 19 from Arthur Road jail in Mumbai where he has been lodged.
Inspector General of Prisons Maharashtra Meeran Borwankar refused to respond media queries on the execution of Kasab.
Scores of curious onlookers started crowding in front of the jail as the news spread in the city.
There was, however, no official word or briefing by the jail authorities on the last rites of the hanged convict.
Union Home Minister Sushil Kumar Shinde said Pakistan was informed about the execution of Kasab.
"With the execution of Kasab, we have completed the judicial procedure of 26/11 case." Shinde said in Delhi.
The Indian High Commission in Islamabad informed Pakistan government about Kasab's hanging through letter, he said, adding Pakistan refused to take the letter, which was then sent through fax.
External Affairs Minister Salman Khurshid said the obligation of keeping Pakistan informed about the hanging was fulfilled.
Special Public Prosecutor Ujjwal Nikam, who appeared for police in the case said the hanging is a "victory" for the country. (MORE)