The fishermen from Tamil Nadu stranded in Iran, "are neither allowed to return to India nor allowed to continue fishing for which they were engaged as contract fishing abourers," he said in a letter to the Prime Minister.
"I request you to direct the Embassy of India in Iran to take all measures to ensure the immediate repatriation of these 21 poor innocent Indian fishermen," Mr Palaniswami said.
He said in the recent past, the Iranian employers had not paid the fishermen their share, as per terms of employment.
The kin of the fishermen had made a representation to the authorities in districts including Kanyakumari, seeking steps for their early return,
These fishermen were struggling to make their ends meet and unable to send money to their families back home, Mr Palaniswami said.
The chief minister also urged that necessary steps "be taken to ensure that the fishermen receive their just and due wages."
The 21 fishermen - eight from Kanyakumari district, seven from Tirunelveli district and six from Thoothukudi district - were engaged in fishing in three boats belonging to their Iranian employers for more than six months, he said.
Mr Palaniswami said the fishermen lost hope of receiving a fair remuneration from their employers and requested them to facilitate their return to India which was also refused.
It was "reported that the passports of the fishermen are in the custody of the local employers," who are neither allowing them to continue work nor allowing them to return to India.
The employer reportedly chased the fishermen out of their accommodation and abandoned them in the streets without any shelter, food and security, the chief minister said.
The International Fishermen Development Trust had yesterday highlighted the plight of the 21 fishermen stranded in Iran and urged the Tamil Nadu government to take steps for their safe return.