Apart from Pawar, NCP's second candidate advocate Majid Memon also filed his papers. They were accompanied by Union Minister Praful Patel, senior NCP leader D P Tripathi and state NCP chief Bhaskar Jadhav on the occasion.
Pawar and Memon replace retiring NCP members Y P Trivedi and Janardhan Waghmare.
On his way to the house of elders in the Parliament, 73-year-old Pawar said, "I accept that I have aged. It was a conscious decision."
Pawar, who has won the Lok Sabha elections eight times since he first entered the Parliament in March 1985, founded the NCP in 1999 after breaking away from Congress. The veteran leader, who had mulling to bid adieu to Lok Sabha for long, has earlier served as Defence Minister besides being Chief Minister of Maharashtra thrice.