In order to improve the thermal conductivity of 30 wt% syntheticgraphite (SG)-filled polyketones (POKs), conductive fillers such asmultiwall carbon nanotubes (CNTs) and hexagonal boron nitride (BN)were used in this study. Individual and synergistic effects of CNTsand BN on 30 wt % synthetic graphite-filled POK on thermal conductivitywere investigated. 1, 2, and 3 wt % CNT loading enhanced the in-planeand through-plane thermal conductivities of POK-30SG by 42, 82, and124% and 42, 94, and 273%, respectively. 1, 2, and 3 wt % BN loadingsenhanced the in-plane thermal conductivity of POK-30SG by 25, 69,and 107% and through-plane thermal conductivity of POK-30SG by 92,135, and 325%. It was observed that while CNT shows more efficientin-plane thermal conductivity than BN, BN shows more efficient through-planethermal conductivity. The electrical conductivity value of POK-30SG-1.5BN-1.5CNTwas obtained to be 1.0 x 10(-5) S/cm, the valueof which is higher than that of POK-30SG-1CNT and lower than thatof POK-30SG-2CNT. While BN loading led to a higher heat deflectiontemperature (HDT) than CNT loading, the hybrid fillers of BNT andCNT led to the highest HDT value. Moreover, BN loading led to higherflexural strength and Izod-notched impact strength values than CNTloading.