This paper describes methods to develop nylon6/EPDM TPVs with a high amount of rubber. A lot of literature is available about PP/rubber TPVs; concerning TPVs in which the thermoplastic is an engineering polymer (polyamide or polyester), no information is available. The difficulty to prepare such TPV's is due to the high interfacial energy between the two components. By using a suitable compatibiliser and dynamic vulcanisation, it will be possible to develop nylon6/rubber TPVs, whereby the rubber phase will be finely dispersed in the nylon matrix. The influence of the viscosity ratio rubber/thermoplastic on the blend phase morphology and the mechanical properties will be investigated by changing the molecular weight of nylon6. The morphology development as a function of the mixing time, and also the thermal properties of the nylon6/rubber TPVs are examined.