Nanostructured organic-inorganic composites have been the source of much attention in both academic and industrial research in recent years. Composite materials, by definition, result from the combination of two distinctly dissimilar materials, the overall behavior determined not only by properties of the individual components, but by the degree of dispersion and interfacial properties. It is termed a nanocomposite when at least one of the phases within the composite has a size-scale of order of nanometers. Nanocomposites have shown improved performance (compared to matrices containing more conventional, micron-sized fillers) due to their high surface area and significant aspect ratios - the properties being achieved at much lower additive concentrations compared to conventional systems. In this article, recent developments in the formation and properties of epoxy layered silicate nanocomposites are reviewed. The effect of processing conditions on cure chemistry and morphology is examined, and their relationship to a broad range of material properties elucidated. An understanding of the intercalation mechanism and subsequent influences on nanocomposite formation is emphasized. Recent work involving the structure and properties of ternary, thermosetting nanocomposite systems which incorporate resin, layered silicates and an additional phase (fibre, thermoplastic or rubber) are also discussed, and future research directions in this highly active area are canvassed.