In this study, three different techniques are used for the production of epoxy-boron nitride nanocomposites in an attempt to evaluate the role of particle dispersion and distribution in the dielectric response of nanocomposites. Although the produced nanocomposites have a different particle distribution which is evaluated with a scanning electron microscopy analysis, they exhibit the same trend and similar dielectric response. The slight differences between the samples are plausibly caused by the different amount of water content rather than the particle distribution. The presence of water inside the samples is evaluated with a thermogravimetric analysis including also an analysis with a mass spectrometer. Finally, it is proposed that the dielectric response of the nanocomposites is mainly dictated by two competing mechanisms, namely polymer re-organization and water uptake, and it is suggested that high levels of reproducibility can be achieved when the particles are effectively dispersed in the polymer matrix regardless the particle distribution.