SRK also wished the "Dil Dhadakne Do" star, who turned 59 on Thursday and added that the actor will always be 42-years-old for him.
"Happy Birthday to @AnilKapoor, my first friend in Mumbai and I know will always be there till the last. You will always be '42' for me. Love you." SRK tweeted.
Shah Rukh and Anil have worked together in the 1995 film "Trimurti", which was directed by Mukul Anand.
On the silver screen, Anil was last seen in Anees Bazmee's "Welcome Back".
SRK will next be seen in Maneesh Sharma's directorial "Fan", which is slated to hit the screens on April 15, 2016.