Underutilized fruits benefit humans through their adaptability to the local environment. However, their low economic value and limited utilization contribute to their gradual disappearance from the local community. Therefore, studying their biological properties and potential applications may support conservation efforts and encourage their reintroduction into local communities. Three commonly found fruit plants in Bireuen Regency Aceh, namely Lepisanthes rubiginosa, Mangifera quadrifida and Annona reticulata, were once valued by local communities. Still, nowadays the presence is often ignored due to low economic value. As fruit is usually rich with bioactive compounds, research has been conducted to elucidate the biological potency as a means of conservation and reintroduction of the fruit to the community. DPPH free radical scavenging activity, antibacterial potential, total flavonoid and phenolic content of methanol extracts of L. rubiginosa, M. quadrifida and A. reticulata were conducted. Results showed that all three extracts exhibited significant free radical scavenging activity, with M. quadrifida demonstrating the highest potency, as indicated by the lowest IC50 value of 0.0012 mg/ml. Flavonoid content and TPC results also in correspondence with M. quadrifida showed the highest flavonoid content 282.11 ± 0.1 mg QE/g extract and 655.26 ± 0.1 mg GAE/g extract, consecutively, M. quadrifida also showed the strongest growth inhibition of S. aureus and E. coli. These results suggest that underutilized fruit may serve as valuable sources of flavonoids and exhibit promising biological potential.