In general, lower viscosity of materials leads to desirable nano-pattern replication characteristics in injection molding processes. However, such materials do not meet the properties required for manufacturable products owing to their poor mechanical properties. In this study, we blended a small amount of dendrimer with high-viscosity polyamide 6 to lower viscosity and enhance flowability of the polymer blend while maintaining desirable mechanical properties. It was observed that the flowability of the polyamide 6/dendrimer blend increased significantly with an increase in dendrimer content without affecting the mechanical properties of high-viscosity polyamide 6. To investigate the nano-pattern replication characteristics of the blend, injection molding process and the mold of metal stamp were used to manufacture a nano-pattern specimen. Blending more than 0.6 wt% of dendrimer with high-viscosity polyamide 6 significantly improved its nano-pattern replication characteristics and flowability.