Pattukkottai Assembly constituency is located in Thanjavur district and is part of the Thanjavur Lok Sabha seat. Historically, the seat was a stronghold for the Indian National Congress (INC) before becoming a competitive ground for the DMK and AIADMK. In the 2021 Assembly elections, DMK’s K. Annadurai won the seat by securing 79,065 votes. He defeated AIADMK’s N. R. Rengarajan, who secured 53,796 votes. The margin of victory stood at 25,269 votes. In the 2016 Assembly elections, AIADMK’s C. V. Sekar won the seat with 70,631 votes, defeating INC’s K. Mahendran, who secured 58,273 votes. The margin of victory was 12,358 votes. In the 2011 Assembly elections, INC’s N. R. Rengarajan won the seat with 55,482 votes, defeating AIADMK’s N. Senthilkumar, who secured 46,703 votes. The margin of victory stood at 8,779 votes.