We report the growth of InP layers using low-pressure metalorganic vapor phase epitaxy on buffered HF-treated Si(111) surfaces, both normally oriented and 3.8° off, toward [Formula: see text]. The InP layers grown on normally oriented Si(111) show the presence of roughly regular terraces, which may be associated with antiphase domains, whose width increases rapidly with the epilayer thickness. The average dislocation density at the top surface is as low as 4 × 105 cm−2 for 4.8 μm thick epilayers. Transmission electron microscopy observations show a rapid decrease of threading dislocation densities with increasing distance from the interface, due principally to their coalescence, as determined from X-ray diffraction analysis. This indicates a high reaction constant between dislocations, of 1.8 × 10−5 cm.