New derivatives of thiophene-fused DCNQI and their CuI complexes have been prepared. Among those, beta,beta’-dimethyl derivative (2) afforded a single crystal of complex (2)(CuI), suited for an X-ray analysis and its crystal structure has been determined. The structure is built up of the zigzag ladder of CuI polymer. Bidentate ligand molecules of 2 bridge the CuI ladders by coordinating the CN group to Cu of the ladder. The acceptor pi-plane is arranged face-to-face with interplanar distance of 3.56 Angstrom. The room temperature conductivity of (2)(CuI)(2) was 7.6 X 10(-3) Scm(-1) with semiconductive behavior in the temperature dependent conductivity.