Nanomaterials, especially silver nanoparticles (AgNps) offer unique optical, chemical and physical properties when compared to properties of bulk materials due to their plasmonic ressonance band. Despite AgNps synthesis by chemical reduction is not new, their stability is a crucial factor for a good applicability. AgNps were characterized by UV-vis spectroscopy. Different reports found in literature related to concentrations of used reagents in nanoparticles synthesis are scares when one take into account the high control that is required to avoid nanoparticles aggregation. This study aims to evaluate the concentrations of the reducing agent -NaBH 4 (factor a), stabilizing agent -PVA (factor b) and AgNO 3 (factor c) through a factorial design 2 3 with three center points of face centered to evaluate the influence of reagents and their concentrations on AgNps stability. The interaction between factors "a" and "c" showed a positive significant value when concentrations are modified from level (-) to level (+) of these two variables. It can be observed an increase of plasmonic band absorption peaks of 18.4% indicating synergism between variables a and c. However, one can notice a decrease of 3.91% of peak's incidence when factor "b" concentrations are increased. It can be inferred that low PVA concentrations (≤ 0.5%) assist the AgNps stability and above this value PVA acts as a chemical inhibitor. Analysis of variance indicated a coded quadratic model of second order. Plots of response surface showed that the ideal synthesis of AgNps happens on the ratio NaBH 4 (mmol) : PVA (%) : AgNO 3 (mmol) of 4:1:2.