Viswanath started his professional life as an audiographer. His filmmaking career began under director Adurthi Subba Rao after a brief stint as a sound engineer, and he later went on to work as an assistant director for Telugu film Pathala Bhairavi in 1951. K Viswanath Passes Away at 92; SS Rajamouli, Jr NTR and Others Remember the Veteran Telugu Filmmaker.