He submitted his formal resignation letter from the Shirdi constituency in Ahmednagar district, from where he was elected five times, to Assembly Speaker Haribhau Bagade.
Since the past few weeks, Vikhe-Patil has been in constant touch with several top BJP leaders, including Chief Minister Devendra Fadnavis, and has broadly indicated that he would be joining the ruling party soon.
On the eve of the last Lok Sabha elections, his medico son Sujay Vikhe-Patil had dropped a bombshell by quitting the Congress to join the BJP and later contested - and won the Ahmednagar parliamentary seat.
A sulking Radhakrishna Vikhe-Patil had refrained from campaigning for the Congress-Nationalist Congress Party in Ahmednagar region.
After the elections in which the National Democratic Allinace returned to power, he had written to Congress President Rahul Gandhi, and discussed with party General Secretary and Maharashtra in-charg) Mallikarjun Kharge on why he was planning to quit before tendering his resignation as Leader of Opposition.
BJP circles hint that in view of the upcoming Assembly elections around October, Vikhe-Patil may be rewarded with a cabinet post.
Shortly after Vikhe-Patil's quitting as MLA, expelled Congress legislator from Sillod in Aurangabad, Abdul Sattar A. Nabi claimed that at least 8-10 Congress legislators were in touch with the BJP and called the state party leadership as "a total failure".
However, state Congress President Ashok Chavan dismissed the claims and contended that none of the disgruntled legislators are planning to quit.
For the Congress, a fresh challenge is to appoint a new party leader for the monsoon session of the state legislature commencing on June 17 for better coordination with the NCP and allies, and lay the groundwork for the Assembly polls.
( With inputs from IANS )