Polyether-ether-ketone (PEEK) is a high-performance thermoplastic with high heat-, high chemical-, high water-, and high wear-resistance. Its strength and durability also make it highly accepted for a range of industrial applications. 3D printing of PEEK filaments offers a unique quality and flexibility in making PEEK parts for low-volume production or special designs. This study investigates the impact strength of 3D printed PEEK materials. The specimens are fabricated using a fused deposition modeling (FDM) based 3D printer and tested by a pendulum impact tester in compliance with ASTM standard. The testing result is discussed with respect to the processing parameters and the annealing treatment. Impact strength comparison of PEEK materials manufactured by 3D printing and by conventional production is also conducted.