He is member of Karnataka Legislative Assembly from Indian National Congress (INC) representing Madhugiri.
His public life began around the same period when he served as secretary of the Kyathasandra taluk unit of the Indian National Congress.
In 1976, he was elected president of the nagar panchayat Kyathasandra, before heading INC's Youth Congress wing of the Tumkur district-unit between 1980 and 1984.
[1] Rajanna was elected to the Karnataka Legislative Council in 1998 and completed the six-year term till 2004.
[4] In May 2023, he was appointed a cabinet minister,[5] and was handed the Cooperation portfolio (excluding Agriculture Marketing).