The use of x‐ray diffraction techniques for studying twin microstructure and particle‐size analysis of (111) CdTe and (111) ZnTe layers grown by metalorganic chemical vapor deposition on GaAs substrates is demonstrated. Two types of twins, lamella and double positioning, were identified, both composed of small particles (domains). A procedure is presented for the determination of the particle thickness and width as well as the lamella thickness. CdTe(111)Blayers are typically characterized by a two‐dimensional growth mechanism, smooth surface appearance, relatively high growth rate, and lamella twin structure. On the other hand, the (111)A‐oriented layers (CdTe and ZnTe) exhibited a three‐dimensional growth mechanism, rough surfaces, low growth rates, and double‐positioning twins with a preferred twin orientation of the substrate.