Silver nanowires (AgNWs) were synthesized by a modified polyol method and evaluated for their structural features and anticancer activity against Ehrlich ascites carcinoma (EAC) cells in vivo. The AgNWs were characterized by UV–vis spectroscopy, zeta potential analysis, dynamic light scattering, FESEM, TEM, and EDS to confirm their optical response, morphology, and elemental composition. The nanowires showed a plasmonic absorption band at 385 nm, a near-neutral zeta potential, and a mean diameter of 71.58 ± 22.78 nm, although minor secondary morphologies were observed. In the EAC mouse model, AgNWs reduced viable EAC cell counts in a non-linear dose-dependent manner, with the lower dose showing stronger inhibition than the higher dose. These findings suggest that AgNWs possess measurable anticancer activity, while also indicating that dispersion state and dose-dependent behavior require further mechanistic study before translational use can be considered.