ABSTRACTPolyamide‐type composites with improved thermal conductivity are prepared by using polyamide 6(PA6)/polyamide 6,6 (PA66) 1:1 blend as the matrix and aluminum nitride (AlN) as the filler through melt compounding. Field emission scanning electron microscopy coupled with energy dispersive spectrometry (EDS) mapping of Al is used to investigate distribution of AlN. Differential scanning calorimeter is used to investigate the crystallization behavior of the composites. The thermal conductivity of PA6/PA66/AlN composite with 50 wt % AlN is 1.5 W m−1 K−1, 88% enhancement compared to those of single polymer based PA6/AlN or PA66/AlN composites. The reason for the improved thermal conductivity is the increased effective volume concentration of AlN in one (probably PA66) phase. The experimental data are fitted into Bruggeman and Agari–Uno model. Composites with similar thermal conductivity are also prepared using silicon carbide as the filler instead of AlN, showing that using PA6/PA66 1:1 blend as the matrix is a universal method to prepare thermally conductive composites with less filler loading. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45371.