Piper betle Linn. (Family: Piperaceae) is a common plant cultivated in Asian countries. The aim of this study was to evaluate the antioxidant potential and possible applications of P. betle leaves grown in Sri Lanka. This was carried out using P. betle cold ethanolic extract (CEE), hot water extract (HWE) and essential oil (EO). The initial free radical scavenging activity of CEE was higher than that of butylated hydroxyl toluene (BHT). Further, antioxidant activity of CEE, EO and HWE did not significantly deviate from the initial antioxidant activity up to 12 months. However, at elevated temperature (200 °C) antioxidant activity was significantly reduced (EC50 values of CEE, EO and BHT increased by fourfold and HWE by threefold) compared to their initial values. The reduction of antioxidant activity of CEE was lesser than that of BHT. Peroxide values (PV) were significantly lower in CEE-incorporated coconut and palm oil samples compared to that of BHT-treated samples. Moreover, CEE extended the shelf-life of potato chips and increased the stability of Aloe gel.