Electrolysis of aqueous silver nitrate solutions coated by monolayers, prepared from dihexadecyl phosphate, dipalmitoylphosphatidic acid, dioleoylphosphatidic acid methyl ester, dipalmitoylphosphatidylethanolamine, and phosphoric acid n-hexadecyl N-(O-vinylbenzoyl)-11-aminoundecyl ester, has resulted in the two-dimensional electrocrystallization of 50- to 70-nm-diameter silver particles at potentials more negative than those used for silver ion reduction at electrode surfaces. In contrast, no silver particle formation was observed under monolayers prepared from surfactants having positively charged or bulky headgroups. Chronoamperometry and cyclic voltammetry have established the importance of strong silver ion complexation in kinetically controlled electroreduction under monolayers.