Abstract: The total phenolics were extracted from Rhodomyrtus tomentosa whole fruit with 95% methanol and quantified by Folin method. The extract was subjected to assessing its antioxidant potential using DPPH, ABTS and Hydroxyl system, and its acetylcholinesterase (AchE) inhibitory activity was tested by modified Edman method. The results showed that the fruit extract contained high levels of total phenolics (2.45 mg/g DW), and it was found to be effective scavenger against DPPH radical, ABTS and hydroxyl radical. The activities increased in a concentration dependent manner. IC50 values were 120.78, 25.44 and 194.09 μg/mL, respectively. It also exhibited strong inhibitory activity against acetylcholinesterase in a concentration dependent manner, IC50 was 15.07 μg/mL. In conclusion, the polyphenol extractives from R. tomentosa fruit had strong antioxidant potential and acetylcholinesterase inhibitory activity.