The influence of Multi-Layer Graphene (MLG) and nanoclay on the performance of epoxy based nanocomposites has been studied. First, the theoretical aspects of nano-fillers and their impact on mechanical, thermal, and electrical properties of nanocomposites have been discussed. Then, nanocomposites were produced with varying weight fraction of nano-fillers (0.05, 0.1, 0.3, 0.5, and 1.0 wt%). It was observed that organic solvent, if not completely removed, causes porosity which acts as stress raiser and deteriorates the mechanical properties. The influence of reinforcement morphology on the mechanical properties of epoxy nanocomposites was studied using two nano-fillers: MLG and nanostructured graphite (NSG). It was observed that mechanical properties of nanocomposites were higher when the filler had corrugated and fluted topography. Modeling and simulation of epoxy nanocomposites were carried out using finite element method. It was observed that graphene based nano-fillers are efficient in scattering and dissipation of heat flux thereby increasing the thermal stability of epoxy nanocomposites. The macro-topography of bulk samples of monolithic epoxy and nanocomposites was modified by treating the samples with the abrasive papers. It was observed that surface notches, when exceed certain depth, cause degradation in mechanical properties. It was further observed that tensile properties are more sensitive to topography than flexural properties.