Mr Vaiko was proceeding by foot with his followers on the outskirts of the city, demanding introduction of prohibition in the state.
Ms Jayalalithaa, who was passing by, stopped her car, got out and enquired about Mr Vaiko's health and his family.
The MDMK leader in turn explained the purpose of his walk and extended an advance birthday greeting. Ms Jayalalithaa's birthday falls February 24.
This was their first meeting after a long time.
In the 2011 assembly elections, the MDMK quit the AIADMK alliance as it was not given sufficient number of seats to contest.
In December, MDMK propaganda secretary Nanjil Sampath joined the AIADMK.