The Dravida Munnetra Kazhagam-led (DMK) front won the elections, with the DMK emerging as the single-largest party with 96 seats, and its leader, M Karunanidhi was sworn in as Chief Minister for a fifth and final term.

This election marked the first time the state saw a hung assembly with no party gaining a majority of its own.

As a result, DMK formed a minority government with its allies, which is the first in the state since the 1952 election.

The election marked the electoral debut of the actor Vijayakanth and his political outfit, the Desiya Murpokku Dravida Kazhagam (DMDK).

There were two notable new parties — Desiya Murpokku Dravida Kazhagam (DMDK) formed in September 2005 by actor-turned-politician Vijaykanth, and Lok Paritran formed by Indian Institutes of Technology graduates in February 2006.

Before the 2009 Lok Sabha Elections, the Pattali Makkal Katchi left the DMK, citing differences with its leader M. Karunanidhi, and joined the AIADMK, and the Third Front.

Due to the loss of key allies after the previous election, the All India Anna Dravida Munnetra Kazhagam (AIADMK), ended up losing both the 2004 Lok Sabha Election and the 2006 State Assembly Elections, to DMK led coalition that consisted of Dravida Munnetra Kazhagam (DMK), and former allies of AIADMK, Indian National Congress, left parties (Communist Party of India, Communist Party of India (Marxist)) and Pattali Makkal Katchi.

[8] Pattali Makkal Katchi, and its leader Dr. Ramdoss and left parties would also end up joining the AIADMK led front, leaving the DMK coalition ahead of 2009 Lok Sabha General election.