The pact, signed after summit talks between President Pratibha Patil and her South Korean counterpart Lee Myung-bak provides legal ground for South Korea's participation in India's atomic power plant construction projects.
South Korea has now become the ninth country which had signed nuclear agreement with India after it got the waiver from the Nuclear Suppliers' Group (NSG) in 2008.
The others are the US, France, Russia, Canada, Mongolia, Kazakhstan, Argentina and Namibia.
South Korea operates 20 nuclear plants that generate some 35 per cent of its electricity needs, and is keen to export its technology to fast developing countries like India.
"The two countries have just concluded and signed a bilateral agreement on cooperation in the peaceful uses of nuclear energy," said Sanjay Singh, Secretary (East), Ministry of External Affairs.
"It is like other civil nuclear agreements signed between India and other countries. We look forward to Republic of Korea for becoming one more partner in the development of civil nuclear energy in India," the official said without divulging further details on the agreement and its mandate but termed the deal as a "win-win" for both the nations.
South Korean presidential spokesman Park Jeong-ha said he anticipates that the two countries could launch negotiations on a reactor construction project in the future.
Both India and South Korea decided to start talks on civil nuclear cooperation during a meeting between Prime Minister Manmohan Singh and South Korean President Lee on the sidelines of the ASEAN Summit in Hanoi in October last year.
Seoul's state-run Korea Electric Power Corp. (KEPCO) has been seeking cooperation with Nuclear Power Corporation of India Limited to get into India''s nuclear power plant construction market, South Korea's Yonhap news agency reported.
The nuclear agreement was signed by Dr Srikumar Banerjee, Secretary Department of Atomic Energy and Kim Sung Hwan, Foreign Minister of the Republic of Korea.
Earlier, Patil and her South Korean counterpart Lee held a 20-minute restrictive meeting followed by a delegation level talks for over an hour at the ''Blue House'', official residence of the Korean President.
Patil is on a week-long tour of Korea and Mongolia.
Besides the agreement on nuclear cooperation, the two sides also signed a Memorandum of Understanding on media exchanges and another agreement on administrative arrangements to provide social security to people working in India and Korea.
The MoU on media was signed by Singh and Choung Byoung-gug, Minister for Culture, Sports and Tourism.
The third agreement for administrative arrangements for social security was signed by Skand Ranjan Tayal, Ambassador of India to South Korea and Chin Soo Hea, Minister of Health and Welfare.