Shweta Naagu is a Devotional movie its about a snake story, In which Madhumati (Soundarya) is a research scholar. Her thesis subject is a study on snakes. Her professor (Sarath Babu) tells her about 'naga sastram' (science of snake) that is written by few priests a few centuries back. That naga sastram is kept in Nallamalla forests with a snake protecting it round the clock. Madhumati reaches Nallamalli forests and tries to procure Naga Sastram. In this process she encounters Swetha Nagu (white snake). Swetha Nagu is after Soundarya to bite her. A Sadhu tells her that she killed a snake in her past life and that snake is seeking revenge now. He also gives her a talisman to protect herself from swetha nagu. The rest of the film is all about how Madhumati fights with Swetha Nagu and wins with the blessing of Naga Devata.