We have performed microencapsulation of phenyl acetate using poly(urea-formaldehyde) as a shell material, and studied the effect of agitation rate, core/shell mass ratio, surfactant concentration, and reaction time on capsule characteristics such as size, shell thickness, and surface morphology. The formation of microcapsules was confirmed by FTIR and TGA, and capsule characteristics were studied by optical microscopy and FE-SEM. Capsule size and shell thickness reduced with increasing agitation rate. As the mass of shell material was increased, shell thickness and nanoparticles on capsule surface increased. Capsule size and shell thickness decreased with increasing the concentration of a surfactant. Increasing reaction time caused increased capsule yield and shell thickness.