Swami Sandeepananda Giri's Ashram here was vandalised by a group of unidentified men early on Saturday.
Two cars and a scooter, belonging to the Ashram, were also set ablaze by the assailants.
Sandeepananda Giri is one of the supporters of the Supreme Court's verdict that allowed the entry of women of all ages inside Kerala's Sabarimala Temple.
He has been allegedly receiving threats for hailing the top court's order.
Kerala Chief Minister Pinarayi Vijayan, accompanied by state finance minister Thomas Issac and state Devaswom Minister Kadakampally Surendran, visited the preacher and condemned the attack on his Ashram.
"Physical attacks happen when you can't deal ideologically. Will not allow anyone to take law and order in their hands. Those who are intolerant towards Swami's activities attacked his ashram," Vijayan said.
The Sabarimala Temple witnessed strings of protests by devotees and priests as few women tried to reach the sanctum sanctorum following the apex court's ruling that came on September 28.
So far, over 2,800 people have been arrested and 490 cases have been registered against protestors who prevented women from entering the temple.