In the present study, the bark extract of Acacia nilotica plant was used to green synthesis and Characterization of Silver nanoparticles and check their insecticidal potential against three important mosquito vectors such as Aedes aegyptii, Anopheles stephensi and Culex quinquefasciatus. Our research aims to investigate the therapeutic potential of plant extract combined with nanoparticles. The synthesized silver nanoparticles were characterized by UV-Visible spectroscopy (UV-Vis), Fourier transform infrared Spectroscopy (FT-IR), and scanning electron microscopy (SEM) with EDax techniques (EDAX) and X-ray diffraction (XRD). UV-Vis confirms with the peak at 420 nm showed the synthesis of silver nanoparticles. SEM confirms the spherical shape of nanoparticles and EDAX revealed chemical components of Ag, N, and Oxygen with a strong elemental signal in association with distinct peak for Ag was confirmed at 3.15keV. XRD was determined the crystalline properties of the silver nanoparticles (AgNP). The antioxidant potential of Acacia nilotica bark extract using AgNP was determined by DPPH, hydroxyl and ABTS free radical scavenging assays. DPPH and hydroxyl activities of AgNP showed the highest inhibition of 63% and 84%, while ABTS analysis showed 58%. Antibacterial activity shows highest level of activity against S. pyrogens, P. aeruginosa and P.vulgaris. Larvicidal potential of AgNPs recorded good mortality rate against Aedes aegypti., Anopheles stephensi., Culex quinquefasciatus. This study confirms the maximum activity of AgNPs and acts as larvicidal, adulticidal, antimicrobial, and antioxidant agents.