The synthesis of nanosized powders With targeted properties and their assembly is of considerable importance to the microelectronics industry because of the pervasive drive to miniaturize components. In the current work, synthesis of nanosized silver (Ag) metal platelets was studied. The platelets were synthesized in the lamellar bilayer phase region (neat phase D) of the oetylamine-water binary system. Amylamine was used as cosurfactant to increase the phase stability of the lamellar region. The influences of the synthesis conditions and the concentrations of the system components on morphology and size of the platelets were examined. Low-angle X-ray diffraction studies revealed that the water/surfactant molar ratio (R) has a strong influence on the thickness of bilayers (d(1) + d(2)) and consequently particles grown in them. Atomic force microscopy (AFM), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) studies have shown the effect of R on platelet thickness (t) and face size (a). Thickness and face area of platelets is controlled by regulating the bilayer dimensions by changing R. Platelets with face sizes ranging from 12 to 83 nm and thicknesses from 0.3 to 5 nm have been synthesized at room temperature.