The generation of misfit dislocations has been investigated on epitaxial silicon wafers with boron‐doped substrates, as a function of the film thickness and the misfit resulting from the difference in lattice parameters between the film and the substrate. Critical values of the film thicknesshcand of the misfitfcrequired to form misfit dislocations were found to behc=2.4–‐2.9 &mgr; for the interfacial misfit of 0.019% andfc=0.003–0.006% for relatively large film thickness, where the interfacial energy approaches that of infinitely thick film. These results were analyzed in terms of van der Merwe's theory and a good agreement was found between the experiment and the theory. The density of misfit dislocations was observed to increase with the interfacial misfit or with the film thickness. The relation between bending of the specimens associated with the misfit and the film thickness was studied. Some properties of misfit dislocations are described.