The leader is the latest among political personalities to take to the micro-blogging site with his ID tentatively titled @Kalaignar 89, party sources said.
Twitter was abuzz with both supporters and critics reacting to the latest move, with tweets welcoming him ranging from local politics to alliance issues.
A core-team was behind the leader's latest effort, sources said, adding, he will monitor the tweets.
Karunanidhi has joined the likes of octogenarian BJP leader L K Advani, who frequently 'tweets' his views on key issues.
