The purpose of research on metals (M) deposited onto self-assembled monolayers (SAMs) is to understand the interactions between the metal and eventually metal oxide overlayers on well-ordered organic surfaces. Applications of M/SAM and inorganic/SAM research results to the understanding of real inorganic/organic interfaces in vacuum and under environmental conditions can potentially play a key role in the development of advanced devices with stable interfacial properties. The results of M/SAM studies to date are reviewed, M/SAM combinations ranked according to reactivity and penetration, and specific examples of reactive interfaces (Cu/COOH, and Cr/COOH) and nonreactive interfaces with penetration (Ag/COOH) are used to illustrate the extremes.