Piper sarmentosum Roxb. is well known as kadok. It is a small plant that grows only to a height of half a meter. It is utilized as a medicinal herb. Growing and newly planted samples of P. sarmentosum are also observed as landscape plants. The species is reported to contain flavonoids. In this study, an automated instrumentation was selected to observe the chemical profile by using High-Performance Liquid Chromatography (HPLC). The on-site method was differentiated with the published procedure, of the national herbal monograph. The mobile phase was opposed to the gradient elution of water and methanol. Instead, the solvent consisted of 0.3% formic acid and acetonitrile. In the findings, the HPLC chromatograms displayed five acceptable peaks, one of them was considered as the minor component. In comparison with the online data, five biomolecules were possibly detected in the methanolic extract, comprising caffeic acid, amurensin, a flavonoid glucoside, rutin, p-coumaric acid, and quercetin. It is hoped that the research would contribute to the sustainability of this traditional plant.