This article discusses a technique based on combination of multimode resonators MMR and complementary split ring resonators CSRR to design multi notch-bands ultra wide-band UWB band-pass filters BPF. The proposed structure consists of two parallel multimode resonators, resulting in a dual notch-band UWB BPF, integrated with a single cell of CSRR to realize the third notch-band. The mechanism of realizing the notch-bands is mathematically presented and a triple notch-bands UWB BPF is designed, simulated and fabricated. The overall size of the proposed filter is reported to be around 36 × 7.7 mm2 where a size reduction of around 35% is demonstrated in comparison to the conventional filter. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:375-381, 2014.