He appeared in the 1981 film Elippathayam (The Rat Trap), an allegory about the collapse of the feudal system in Kerala. He won the national award for best actor in 1981 for the Malayalam movie Oppol.
He was born on 4 April 1933 in Chemmencherry in Calicut, India. His father Raman Nair was a store owner and his mother Devaki Amma was a housewife. Prior to his entry in films, he worked as a mechanic in Calicut and owned a metal workshop. At the time he was associated with Sangammam Theatre in Calicut. After his marriage to Sharadha, he moved to Shornur in Palakkad district.
His first movie, Nizhalattam in 1972 was directed by P N Menon. Balan K Nair has acted in over 300 films in Malayalam, mostly as villain. He won Kerala state award for best acting in Adhiti and Thacholi Ambu. He won Bharat award for best acting in 1981 for his role as a reformed military officer in Oppol.
Some his well-known movies are Ee Nadu, Aaryan, Oru Vaddakan Veeragatha. His last movie was Kadavu in 1990, in which he played the role of a Muslim oarsman.