This paper describes ways in which the interface between II–VI and III–V semiconductors can be controlled so as to suppress or alter commonly observed interfacial reactions. This will be done using CdTe/InSb and CdS/InP heterostructures as examples. In the case of CdTe/InSb a modification of the interfacial properties is achieved by a variation in the II/VI ratio offered to the surface during growth, while the influence of Sb interlayers is studied for CdS on InP. Information on the interface properties is obtained from Raman spectroscopy. While structural and electronic properties of the II–VI layer can be deduced from the scattering intensities of its characteristic vibrational modes, the formation of interfacial compounds is observed by the appearance of scattering intensity in a different spectral range, which is consistent with the formation of III2VI3 compounds. The potential of Raman spectroscopy for on-line in situ monitoring of growth processes will be displayed.