A scanning tunneling microscope (STM) in ultrahigh vacuum has been used to investigate the growth, morphology, and surface atomic structure of ultrathin titanium silicide films on Si(100) substrates. Microstructural considerations have been used to identify various stages of the silicide growth. Methods for STM crystallography have been developed and used to identify possible epitaxial silicide/silicon relationships based on morphological considerations. Atomic resolution images of a titanium silicide crystallite have identified a 2×2 silicon termination of a C54‐TiSi2(111) surface. It is shown that unambiguous identification of epitaxial relationships requires images of the atomic structure of the silicide crystallite surfaces in addition to morphological information. ©1995 American Institute of Physics.