A novel heptacyclic bisindoloquinoline-based organic semiconductor has been synthesized, characterized, and used to fabricate single-crystal field-effect transistors. A synthetic route was developed for the synthesis of heptacyclic bis(indolo(1,2-a))quinoline via an intramolecular cyclization of anthrazoline derivatives. Single-crystal X-ray structure revealed that the seven fused rings of bis(indolo(1,2-a))quinoline are relatively coplanar and lead to slipped face-to-face stacking with the shortest intermolecular spacing of 3.3 angstrom. Single-crystal field-effect transistors based on the bis(indolo(1,2-a))quinoline had carrier mobility as high as 1.0 cm(2)/V s with on/off ratios greater than 10(4).