Yadav was 74 and is survived by his wife, four sons and a daughter.
An MLA from Jehanabad Assembly constituency, Yadav breathed his last at a private hospital in the state capital where he had been undergoing treatment for the past one week.
Yadav had contracted dengue some time back while he was in his constituency and his condition worsened last week when he fell down and suffered head injuries following which he was admitted to the hospital here.
The chief minister also announced that the last rites of the deceased MLA will be performed with full state honours.
RJD supremo Lalu Prasad condoled Yadav's death calling it "a personal loss and also a loss to the RJD family".
Union Ministers Ram Vilas Paswan and Ram Kripal Yadav, Bihar Deputy Chief Minister Sushil Kumar Modi and state minister Nand Kishore Yadav also expressed grief at the death of Yadav.