[1][2][3] Thilakan was known for his elaborate method acting, realistic and spontaneous appearances[4] and is considered to be one of the greatest actors in Indian Cinema.

He worked with the Kerala People's Arts Club till 1966, followed by stints in Kalidasa Kalakendram, Changanacherry Geetha, and P. J. Antony's troupe.

In 1989 he performed in Mammootty starrer Mrugya, in which his role of a Reverend Father Panangodan was well appreciated by critics and won him many accolades.

In 1987, he was appreciated for his role in Thaniyavarthanam where he portrayed a man who is the head of a family where his nephew played by Mammootty becomes lunatic due to superstition and lack of awareness of mental health.

In the same year, he also played the comic role of Ananthan Nambiar in the cult-classic comedy movie Nadodikkattu, from which several of Thilakan's lines became very popular.

He also starred in the National award winning movie Mathilukal, which was directed by Adoor Gopalakrishnan in which he played the role of a warden of the jail who develops a rapport with the prisoner Vaikom Muhammad Basheer (Mammootty).

Other notable films Thilakan has acted in include Yathra, Mukthi, Kauravar, Moonnam Pakkam, Kilukkam, Namukku Parkkan Munthiri Thoppukal, Mookkilla Rajyathu, Randam Bhavam, Kaattu Kuthira and Yavanika.

1 Snehatheeram Bangalore North and Pallavur Devanarayanan, with Jayaram in Veendum Chila Veettu Karyangal and Sandesam, with Kunchacko Boban in Aniyathi Pravu, with Dileep in Punjabi House and Meenathil Thalikettu and with Prithviraj in Sathyam.

He has played comical roles in films like Nadodikkattu and Pattanapravesham (as a coward underworld don), Mookkilla Rajyathu (as a break-out from a mental hospital), Kuttettan (as a pimp) and Naaduvazhikal (as a good-for-nothing, vain person).

[7] In 2009, he was also seen in Pazhassi Raja, and in the same year he played Mohanlal's father one last time in the actor's 300th movie Evidam Swargamanu.

The exclusion was reportedly due to Thilakan acting in a film by director Vinayan, who till recently headed the rival association MACTA.

[9][10] On 20 February 2010 the CPI's trade union wing, AITUC, came out openly in support of Thilakan, while a senior party leader and Rajya Sabha member K. E. Ismail expressed reservations about political involvement in the issue.

For a long time, Thilakan dealt with numerous health issues like diabetes, hypertension and heart disease.

Finally, he was admitted to Jubilee Mission Hospital in Thrissur on 1 August 2012 after he collapsed during the shooting of the film Scene Onnu Nammude Veedu.