Silver dendritic nanostructures protected by tetrathiafulvalene (TTF) were synthesized via electron transfer from TTF to silver ions in acetonitrile, and the resulting positively charged TTF radical cations interacted with the surface of the silver dendrites. Irregularly shaped particles were visualized by scanning electron microscopy (SEM), while the silver dendritic nanostructures were found by transmission electron microscopy (TEM) due to the crystallization of the oxidized TTF after the removal of the solvent on substrates for SEM and TEM analyses. Energy-dispersive X-ray (EDX) analysis demonstrated that the particles were nanocomposites composed of the silver nanostructures and TTF. Silver and TTF were uniformly distributed in the individual particles. Both the feed molar ratio of AgNO3 to TTF and the addition of poly(vinylpyrrolidone) (PVP) as a stabilizer influenced the size and shape of the silver nanostructures. The X-ray powder diffraction, elemental, and SEM analyses of the isolated products by centrifugation indicated that the TTF-protected silver nanostructures were also formed because of the crystallization of oxidized TTF after the reaction mixture was incubated in the solution for a longer time than 5 days until the transparent solution transformed into a purple translucent dispersion. So crystallization of oxidized TTF played a major role for the formation of silver dendritic nanostructures during the evaporation of the solvent or the incubation of the silver dendrites in the solution.