On Wednesday night, the actors went to visit Thackeray, who is reportedly in critical condition.
"Balasaheb Thackeray: a fighter all his life, fights his life! Prayers needed now! Yes both Abhishek and me were injured with cuts, but are fine and back home... the doctors at Matoshree attended on us," Amitabh tweeted.
Photos: My family is my wonderful gift: Amitabh Bachchan
Amitabh recalled the time when he was recovering in hospital after his near fatal accident on the sets of 1983 film "Coolie", and Thackeray had come to see him.
"When I was flown in to Mumbai from Bangalore in semi-conscious state after 'Coolie' accident, it was his ambulance that took me to Breach Candy Hospital," Amitabh said.
"When I fought for my life after 'Coolie' accident, he came to visit me in hospital, with a cartoon he had drawn - Yamraj defeated! Yamraj - God of Death, defeated by me... wish I was as proficient a cartoonist as he, I would wish to draw that for him," added Big B.
The 70-year-old says Thackeray has always treated him like family.
"When Jaya and I married, he (Bal Thackeray) called us to his house... and the rituals that were conducted was of the 'bahu' coming home! From that day on he always treated us as family," he said.
Photos: Snapshots from the Big B-Jaya love story
Amitabh also revealed how Thackeray supported him while the actor reeled under the Bofors Scandal accusations.
"When the Bofors Scandal accusations on us were at its peak, he called me home and asked 'tell me the truth, are you involved?' When I said 'No!', he said 'Then do not worry about anything. I am with you. You are an actor, go do what you are best at'," he added.