The ultrasonically-assisted hydroacetonic Guaiacum officinale L. bark extract (GoBE) was usedtosynthesizetheAgNPs.Thephytochemicalsinthebarkextractactasmajorcappingand reducing agents and the synthesized AgNPs were investigated for in-vitro antioxidant and anticanceractivities.Thecolourchangeofthereactionmixturefromlightbrowntodarkbrown represents the synthesis of Guaiacum officinale bark extract silver nanoparticles (GoBE- AgNPs). An absorption peak at 410 nm was checked by UV-vis spectrophotometer. FTIR reveals functional group participation in AgNPs capping. Powder XRD and SAED validated thecrystallinityand⁓20–27nmsizewithspherical-shapedAgNPswereobservedinHR-TEM images. The EDS showed the presence of elemental silver. In DLS spectral analysis, the zeta potentialwasmeasuredat-42.2mVandtheparticlesizeanalyzervalidatedthehydrodynamic sizeof+40.7nm.Dose-dependentDPPHradicalscavengingactivityshoweda94.62±0.015% inhibition. GoBE-AgNPs were treated with Human bone marrow neuroblastoma (SH-SY5Y) cancercelllinesat 12.5to200μg/mL concentrations.TheMTTassayshowed 44.85±0.017% cell viability. Annexin V/FITC assay revealed 59.49% apoptosis in cancer cells. AgNPs generated 33.88% oxidative stress in SH-SY5Y cells. The current research ensured the effective antioxidant and anticancer activity of GoBE-AgNPs.