Lunasia amara Blanco or sanrego has long been applied as a pro-fertility agent in folk medicine and it has also been scientifically proven to improve sperm quality in rats. Nevertheless, little is known about the underlying molecular mechanism of improved sperm function upon treatment with sanrego. As such, this study looked into the potential proteomic changes in sperm treated with 60 mg/kg body weight sanrego aqueous extract, in comparison to control. The sperm proteins were subjected to proteomic analysis using 2-D SDS PAGE and MALDI-TOF. The comparison of the sperm protein profiles between treated and control rats revealed two downregulated proteins (cenexin-1 and GLUL) and 11 upregulated proteins (Eno1,PGK2,F1-ATP synthase, FO-ATP synthase, LDHC, GLUL1, ODF2, Sp17, asparaginase, DNAJB13, and tubulin) in treated rats. These proteins have been identified to be mainly involved in energy metabolism, sperm motility, amino acid metabolism, and cell signalling. This improved sperm function in sanrego-treated rats may, thus, be a direct result of proteomic changes, as discovered in this present study.