Zardari made the announcement during external affairs minister S M Krishna's visit to Pakistan.
About 50 more Indian prisoners are believed to be in Malir Jail of Karachi, from where the fishermen were freed this morning and sent to Lahore.
They will cross over to India via the Wagah border tomorrow.
Eighteen-year-old Kishan Chand was among those released today. He could not be released earlier because of illness.
The Pakistan Fisherfolk Forum has called for the release of Pakistani fishermen currently in Indian jails as a reciprocal gesture.
According to information provided by the government in parliament last month, a total of 428 Pakistani nationals, including 85 fishermen, are currently in Indian jails.