Rhinacanthus nasutus(L.)Kuntze (Nagamalli) has long been used in traditional medicine to alleviate abscess pain, tinea versicolor, pruritic rash, ringworm, and skin diseases. The current study sought to explore the existence of numerous phytochemicals as well as the total phenolic, flavonoid, and tannin levels of Rhinacanthus nasutus. In qualitative analysis, the various phytochemical compounds were screened using standard methods. In quantitative estimation, the total phenolic content of each extract was 74.75, 82.47 & 61.25 mg of GA/g extract, the total flavonoid was 368.2, 512.25&160.6 mg of Ru/g extract, and the total tannin was 17.5, 38.5&22.6 mg of CTN/g extract respectively. In-vitro antioxidant activity of ethanolic, hydroethanolic, and aqueous extracts of Rhinacanthus nasutus root was determined by DPPH free radical scavenging assay and determination of total antioxidant activity. The hydroethanolic extract had shown very significant DPPH (1, 1-diphenyl-2-picryl-hydrazyl) radical scavenging activity compared to other extracts. In the DPPH free radical scavenging assay IC50 value of alcoholic, hydroalcoholic, and aqueous root extracts was found to be 282.28, 114.62, and 597.96 µg/mL respectively. The total antioxidant activity of the Rhinacanthus nasutus root extracts was calculated from the calibration curve of ascorbic acid, the results show the antioxidant activity of ethanolic, hydroethanolic, and aqueous extracts were 37.675, 50.85, and 28.225 mg of AA/g extract respectively. The quantitative phytochemical and antioxidant assays showed significant activity for hydroalcoholic extract when compared with ethanolic and aqueous extracts. Thus the present study revealed the comparative phytochemical and in-vitro antioxidant potential of ethanolic, hydroethanolic, and aqueous root extracts of Rhinacanthus nasutus.