Agarkar was born on 4 December 1977 in Bombay. Agarkar started out as a batsman as a child before he was entrusted to cricket coach Ramakant Achrekar sir by his father. On Achrekar's insistence, Agarkar shifted his school from IES to Shardashram Vidyamandir for Class six.

He went on to perform consistently as a batsman scoring heavily in the inter-school Giles Shield tournament for the Under-16s making a triple century when he was 15. He carried the form into the Harris Shield under-19 tournament scoring consistently and showing signs pure batsman

At this stage many Cricket expert compared his shot with Sachin Tendulkar. he began shifting focus to his bowling after it was "pointed out to [him] that it would be hard to make it into the Bombay team as a pure bowler, and that he stood a better chance as an all-rounder".

As a child, Agarkar idolized pacers Kapil Dev, Michael Holding and Ian Botham; later also taking a liking to Allan Donald.
He is the third highest wicket-taker for India in One Day Internationals (ODIs), and has represented India in the 1999 Cricket World Cup and the 2007.

He was also the captain of the Mumbai that won the 2013 Ranji Trophy. Though his performance was rather lacklustre in the initial parts of the 2013 Ranji Trophy, he showed his class towards the end of the tournament. In the quarter final, he scored 52* (53 balls) against Baroda.

Ensure a mammoth total of 645/9 declared. In the semi-final against Services, he scored 145 and made a 246-run 7th wicket partnership with wicket keeper Aditya Tare (120) to rescue Mumbai from 169/6, and take the total to 454/8 declared.

Early in his career, Agarkar broke Dennis Lillee's world record for the fastest 50 wickets in ODIs, achieving the feat from only 23 matches. He held the record from 1998 until 2009, when Ajantha Mendis achieved the feat from just 19 matches.

Agarkar holds the Indian record of scoring the fastest 50 in ODI, he scored 50 off 21 balls. Agarkar also holds another ODI record, which is the quickest in terms of least number of matches played to take 200 wickets and complete 1000 runs.

Agarkar achieved this feat in 133 mts breaking the previous record held by South African Shaun Pollock, who accomplished this feat in his 138th match. 1999-2000 tour of Australia, Agarkar set a record of seven consecutive innings resulting in ducks (four of them first ball).

Agarkar made his ODI debut against Australia at Kochi, on 1 April 1998. He took the wicket of Adam Gilchrist in that match.
20-year-old Agarkar achieved his first Man of the match award in a crucial Coca-Cola champions trophy match against NZ defending just 220 on 17th April 1998

Amongst Agarkar's better performances were his performances in Australia in the Test series of 1999, and also in the test series in 2003. At Adelaide Oval in 2003, Agarkar took 6/41, to help India to win their first test in Australia in over 20 years.

, Agarkar is one of the few players who scored a Test century at Lords against England during India's tour to England in 2002 when he scored 109 not out. Although India lost the test, his batting skills were quite noticeable.
His name written on Lords honours boars.