Polycrystalline ZnS produced by chemical vapor deposition (CVD) is analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) including electron backscatter diffraction (EBSD) to gain insight into the growth mechanism. Epitaxial growth of ZnS (111) layers is indicated in cubic CVD-ZnS. Mechanisms counteracting the growth of large, homogeneously oriented grains are proposed. This includes the summation of faults at low-angle grain boundaries during the deposition of new layers as well as the formation of new growth directions perpendicular to the sides of large grains. Wurtzite could be identified as a product of instable deposition conditions at the beginning and end of the deposition process.