This Letter describes the fastest route to monodispersed silver nanocubes. By adding a trace amount of sodium sulfide (Na2S) or sodium hydrosulfide (NaHS) to the conventional polyol synthesis, the reaction time was significantly shortened from 16-26 h to 38 min. By merely adjusting the reaction time, monodispersed silver nanocubes of 25-45 nm in edge length were rapidly and routinely produced on relatively large scales. These small nanocubes are of great interest for biomedical applications by way of generating gold nanocages with plasmon resonance peaks tunable to the near-infrared region through a galvanic replacement reaction. (c) 2006 Elsevier B.V. All rights reserved.