The topic of polymer nanocomposites remains an active area of research in terms of its potential applications in dielectric and electrical insulation applications. Although more than a decade has passed since Lewis first considered these systems as dielectric materials, the precise effects of incorporating nanofillers into different polymers are yet to be confirmed. While this strategy is generally regarded as a promising means for tailoring insulation performance, the consequences of adding a nanofiller to an insulating matrix are not always positive; for example, where dispersion is poor the breakdown strength can be adversely affected. This paper reports on an investigation into a nanofilled polyethylene system prepared via a solution blending route. Specifically, in this study, the effect of processing and nanofiller dispersion on the structure and physical properties of the nanocomposites that forms was considered. The crystallization behaviour and morphology of the differently processed materials have been evaluated by differential scanning calorimetry (DSC) and polarised optical microscopy (POM). The influence of nanofiller dispersion on breakdown behaviour is also described.