The current investigation involved the silver nanoparticles green synthesis utilizing the aqueous extract derived from the Foeniculum vulgare leaves (AgNPs@FV). The effectiveness of these newly developed nanoparticles in conjunction with radiotherapy was evaluated on lung cancer cells. The synthesized AgNPs@FV underwent characterization through various analytical techniques such as energy dispersive X-ray (EDX), field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and ultraviolet-visible (UV-Vis) spectrophotometry. The efficacy of AgNPs@FV in conjunction with radiotherapy against human lung cancer was assessed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The AgNPs@FV exhibited a spherical morphology ranging in size from 10.16 to 42.74 nm. The EDX diagram of nanoparticles shows energy signals at 3.02 and 2.64 keV, which are attributed to Ag Lβ and Ag Lα, respectively. During the antioxidant evaluation, AgNPs@FV and butylated hydroxytoluene (BHT) displayed IC50 values of 166 and 59 µg/mL, respectively. The cells treated with AgNPs@FV in conjunction with radiotherapy were evaluated using the MTT assay over 48h to determine cytotoxicity and anti-human lung cancer characteristics on normal (human umbilical vein endothelial cell (HUVEC)) and lung cancer cells and exhibited IC50 values of 211, 166, and 296µg/mL against NCI-H2126, NCI-H1299, and NCI-H1437, respectively. Furthermore, the malignant lung cell viability decreased when treated with a combination of AgNPs@FV and radiotherapy. Based on the aforementioned findings, it is possible that the newly developed AgNPs@FV could serve as a novel chemotherapeutic medication or adjunct for addressing lung cancer following the completion of clinical trials involving human subjects.