The methanolic fruit extract of Piper longum and a silver nitrate solution were used to produce silver nanoparticles (Ag-NPs). The phytochemicals present in the extract served as stabilising and reducing agents in this environmentally benign method, allowing stable nanoparticles to develop without the need for harsh chemicals. The obtained nanoparticles were subjected to a series of characterization techniques to confirm their formation and properties. Through optical absorption tests, UV-Visible spectroscopy revealed the surface plasmon resonance band, validating nanoparticle synthesis. Powder X-ray diffraction (P-XRD) revealed information about their crystalline structure. Energy dispersive X-ray analysis (EDAX) was used to confirm the elemental composition, while scanning electron microscopy (SEM) was used to analyse shape and surface characteristics. In addition to structural characterisation, the biological potential of the produced Ag-NPs was investigated. To assess their effectiveness at preventing bacterial growth, antibacterial investigations were carried out against strains of Enterococcus faecalis, Pseudomonas sp., Klebsiella sp., and Vibrio sp. The synthesized nanoparticles exhibited significant cytotoxicity against HeLa cell lines, with an IC50 value of 62.5 μg/mL, corresponding to 54.32 % inhibition. These findings suggest that Piper longum-derived Ag-NPs possess strong anticancer potential against the HeLa (Henrietta Lacks) cell line.