He took his oath in Hindi in the office of Rajya Sabha Chairman Hamid Ansari.
The oath-taking ceremony was done in the presence of V. Narayanasamy, Minister of State in the Prime Minister's office, Rajiv Shukla, Minister of State for Parliamentary Affairs, Ahmed Patel, Political Secretary to Congress President Sonia Gandhi and senior Congress leader Harish Rawat.
After formally signing on as Rajya Sabha MP, Tendulkar was presented a yellow shawl and took part in a photo opportunity with Vice President Ansari and his wife Anjali.
Tendulkar is the first active sportsperson and cricketer to have been nominated to the Rajya Sabha under the Prominent Citizens Quota.
He was nominated to the Upper House along with film actress Rekha and industrialist Anu Aga in April, but had to wait to take his oath until the end of IPL season 5.
The nomination of Tendulkar had sparked a political slugfest with the opposition parties questioning the timing of the move by the government. The Bharatiya Janata Party (BJP) and the Shiv Sena had said that the timing of the nomination suggests that it is aimed at distracting attention from scams.
Tendulkar is the leading run-scorer and century maker in Test and one-day international cricket. He is the first player to score a double century in ODI cricket.
In 2002, just 12 years into his career, Wisden ranked Tendulkar the second greatest Test batsman of all time, behind Donald Bradman, and the second greatest one-day-international (ODI) batsman of all time, behind Viv Richards.
He was also a part of the 2011 Cricket World Cup winning Indian team.