Quantum mechanical/molecular mechanical (QM/MM) methods play an increasingly important role in the study of inorganic systems. From the early application of QM/MM methods, to organometallic catalysts, to the present day use of QM/MM methods in studying bioinorganic systems, the development and uptake of the methodology has been startling. In this review, an outline of the theories for the two major QM/MM schemes (additive and subtractive) is provided. Two case studies, within inorganic chemistry, highlight the strengths of the different approaches. The use of the subtractive QM/MM scheme to decompose a system in terms of specific contributions of chemical moieties and energetic factors provides insight into the nature of how a reaction occurs. While the use of an additive QM/MM methodology in computational spectroscopy has shown the important role of the environment in influencing these parameters. Through the careful callibration of the computational and experimental results, new details about the mechanistic and structural details of inorganic systems are revealed.