Abstract: A dual-band band-pass filter (BPF) using composite right/left handed (CRLH) transmission lines (TLs) is proposed. By properly choosing the parameters of the CRLH TLs, the ratio of the central frequencies of the two pass band can be arbitrary. A prototype operating at 1.47GHz and 2.3GHz is designed, fabricated and measured. Good agreement between Simulated and measured results demonstrates the effectiveness of the proposed structure. The proposed method can mitigate some of the problems between the dual-band work and the need for compact size, which is useful in practical applications.