A method of producing hexagonal plate-like zinc oxide particles having a sharp particle size distribution (i.e., a relatively uniform particle size) at a high weight yield and a high percent yield is provided. The method of producing hexagonal plate-like zinc oxide particles of the present invention comprises mixing by stirring an aqueous hexamethylenetetramine (HMT) solution, a solution of an anionic surfactant in a water-insoluble organic solvent, and optionally water to form a microemulsion containing an aqueous phase of an aqueous hexamethylenetetramine solution having a molar concentration of 0.05 M or more; dropwise adding an aqueous zinc salt solution to the microemulsion; and heating the microemulsion containing the aqueous zinc salt solution to a reaction temperature of 80° C. or more without using any autoclave to form hexagonal plate-like zinc oxide particles.