Throughout his career, Rajendra Nath appeared in numerous films, often portraying the quintessential comic sidekick. Some of his notable movies include:

• "Dil Deke Dekho" (1959): His debut film, where he played the role of Kailash.

• "Jab Pyar Kisi Se Hota Hai" (1961): Portrayed the character Popat Lal, also known as Charlie.

• "Tere Ghar Ke Samne" (1963): Played Ranjit, affectionately called Ronnie.

• "Phir Wohi Dil Laya Hoon" (1963): Took on the role of Difu.

• "Mere Sanam" (1965): Featured as Pyare.

• "An Evening in Paris" (1967): Played Makhan Singh.

• "The Train" (1970): Portrayed Pyarelal.

• "Purab Aur Paschim" (1970): Played Shankar.

• "Hare Rama Hare Krishna" (1971): Took on the role of Toofan.

• "Chhoti Si Baat" (1976): Featured as Mauni Baba.