Due to their layered structure graphene nanoplatelets (GnP) should be outstanding candidates in order to improve the barrier effect of polyamide based films. It is known that well dispersed nanoparticles with a high aspect ratio lead to an increased path of gas diffusion which can be calculated using the Nielson model [1]. Furthermore, the degree of crystallization affects the permeation rate. Both parameters – dispersion of GnP and degree of crystallization – were investigated as a function of different processing parameters and correlated with the permeation rates. Therefore, several commercially available graphene nanoplatelets were melt mixed with semi-aromatic and aliphatic polyamides using a small-scale micro compounder as well as a semi-industrial-scale compounder. Subsequently, films were prepared by compression moulding and film extrusion, respectively. Mixing time, processing temperature and composition was changed in order to investigate the influence of filler and processing parameters on properties like degree of crystallization, viscosity, morphology and permeability. Based on aspect ratio which was determined from rheological measurements permeation rate was calculated and compared with experimental results.