Born in 1934 in Amritsar, Mahendra Kapoor came down to Mumbai when he was 40 days old, and began singing from the age of five, proving very popular among his classmates. At the age of 12 or so he dared visit the late Mohammad Rafi (his idol) alone and the singer told him to pave his original style and not copy him as he was wont to do. 

He also advised him to get a sound classical base, and Kapoor learnt classical vocal music under various teachers like Pt. Husnlal, Pt. Jagannath Bua Purohit, Ustad Niaz Ahmed Khan, Khan Saheb Abdur Rehman, Afzal Husain Khan and Pt. Tulsidas Sharma.He also took part in several inter – collegiate functions and in 1957, won the All India Metro – Murphy competition in which the prizes included a film break. Earlier, Kapoor had recorded for Madmast (1951) under small – timer composer V. Balsara.

Two of the judges in the Metro – Murphy contest, Naushad and C. Ramchandra, simultaneously recorded songs with him. Naushad recorded ‘Chand chupa aur taare doobe’ (Sohni Mahiwal), an eight-minute song that drew the attention of Yash Chopra when he heard the master – tape at Mehboob Studios, for he thought it was Rafi singing. He recommended the voice to elder brother B.R. Chopra who was planning Dhool Ka Phool (1959), Yash’s directorial debut.

C.Ramachandra’s break to him (Navrang) and Chopra’s Dhool Ka Phool (N. Dutta) were both released in 1959, and the song’s proved major hits like the Sohni Mahiwal number, ‘Aadha hai chandrama’. Kapoor’s first duet, ‘Shyamal shyamal’ and ‘Yeh maati sabhi ki kahani kahegi’ from Navrang and ‘Aadhi hai chandrama’ from the latter film proved to be big hits. And Kapoor began an association with BR films that endures this day with their tele – serials.In the '90s, Kapoor sang only in one film - Dillagi. He is not closed to playback, but his voice is considered old for the current stars.