[1] Sumanth's most notable films are Prema Katha (1999),[2] Yuvakudu (2000), Satyam (2003),[3]Gowri (2004),[4] Godavari (2006), Madhumasam (2008), Golconda High School (2011), Malli Raava (2017), and Sita Ramam (2022).

Sumanth, however, remained in India on the request of his grandfather Akkineni Nageswara Rao, who was then on a hiatus from films after a major heart surgery.

The latter had often said that his busy acting career prevented him from fully experiencing fatherhood with his own children, so he wished to raise his first grandchild himself.

[15][16] Sumanth’s lean box office run continued with his next films Pelli Sambandham, Ramma Chilakamma, and Snehamante Idera, despite popular actors from his family Akkineni Nageswara Rao and Nagarjuna sharing screen in two of them.

In addition to commercial success, Sumanth received critical acclaim, with Idlebrain.com commenting, "there is not even a single moment where you can find any shortcomings in his histrionics".

[26] Sumanth next did the lead in Classmates, which generated a curiosity as it was the first time that its director K. Vijaya Bhaskar was without his usual collaborator Trivikram Srinivas as dialogue writer.

[30] Sumanth's following film Golconda High School in 2011 was a sports drama directed by Mohana Krishna Indraganti.

Based on an English Novel "The Men Within" written by Harimohan Paruvu, an ex Ranji Trophy cricketer,[31] this film was positively reviewed and was well received by audiences.

The film however received disappointing reviews, and its theatrical run was further negatively affected by the coinciding 2016 Indian banknote demonetisation.

[37][38] Sumanth made a comeback in late 2017 with the romantic drama Malli Raava, under the direction of debutant Gowtam Tinnanuri.

This film released in February 2021 with 50% theatre occupancy COVID-19 pandemic restrictions and turned out to be commercially unsuccessful despite positive reviews.

Despite the film’s commercial failure, Sumanth's supporting role as his grandfather Akkineni Nageswara Rao was well received in NTR: Kathanayakudu.