Director Rawail had considered Sadhana to play the lead actress of the film. He had waited for months to sign her in his "Mere Mehboob" (1963). But now the actress had developed thyroid problems and took a break from acting for treatment in Boston. Eventually, Rawail signed Vyjayanthimala for the role. Dilip Kumar and Vyjayanthimala who had worked together for "Naya Daur" (1957) were then said to have a romantic affair. The actors parted after Vyjayanthimala worked with Raj Kapoor in the 1964 Hindi film "Sangam". Thus, most of the scenes between the two actors for "Sungharsh" were shot separately.