Persiscaria tenulla, commonly known as Polygonum, is a plant belonging to the family Polygonaceae, which originated from and is widely found in Southeast Asia countries, such as Indonesia, Malaysia, Thailand, and Vietnam. The leaf of the plant is believed to have active ingredients that are responsible for therapeutic effects. In order to take full advantage of a natural medicinal plant for the application in the pharmaceutical and food industries, extraction and separation techniques are essential. In this study, an emerging and rapid extraction approach known as liquid biphasic flotation (LBF) is proposed for the extraction of protein from Persiscaria tenulla leaves. The scope of this study is to establish an efficient, environmentally friendly, and costeffective technology for the extraction of protein from therapeutic leaves. Based on the ideal conditions of the small LBF system, a 98.36 protein recovery yield and a 79.12 separation efficiency were achieved. The upscaling study of this system exhibited the reliability of this technology for large-scale applications with a protein recovery yield of 99.44 and a separation efficiency of 93.28. This technology demonstrated a simple approach with an effective protein recovery yield and separation that can be applied for the extraction of bioactive compounds from various medicinal-value plants. © 2020 by the authors.