A blind narrowband interference (NBI) mitigation approach using a filter bank (FB) is proposed for energy detection (ED) based UWB receiver. By comparing the received signal energy of the filter branches, the proposed FB-ED UWB receiver can achieve effective dynamic NBI detection and mitigation without requiring any transmission of preamble prior. Simulation results show that the proposed FB-ED receiver can significantly improve the bit-error-rate performance of energy detection based impulse UWB transceivers no matter when an NBI is present or not.