The wollastonite was grafted with different silane coupling agents, which could improve interface adhesion. Wollastonite and modified wollastonite-reinforced poly(ether ether ketone) (PEEK) composites were prepared by melt blending. The mechanical properties, rheology behavior, and thermal properties of the composites were investigated. The modified wollastonite-reinforced PEEK composites exhibited better mechanical properties than the unmodified wollastonite-reinforced PEEK composites based on good interfacial adhesion. The composites had lower activation volume and complex shear viscosity. Furthermore, the modified wollastonite-reinforced PEEK composites had higher crystallization peak temperature (T-c) and crystalline fraction (chi(c)) compared with the unmodified wollastonite-reinforced PEEK composites. This study shows that the traditional silane coupling agents could effectively improve the performance of PEEK composites. POLYM. ENG. SCI., 51: 1051-1058, 2011. (C) 2011 Society of Plastics Engineers