A facile three-step synthetic procedure for highly pi-extended heteroarenes, dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) and dinaphtho[2,3-b:2',3'-f]selenopheno[3,2-b]selenophene (DNSS), was established. Solution UV-vis spectra and electrochemistry indicated that they have relatively low-lying HOMO levels and large HOMO-LUMO energy gaps. OFET devices fabricated with evaporated thin-films of DNTT and DNSS showed excellent FET characteristics in air, and the highest field-effect mobility of DNTT- and DNSS-based OFETs is 2.9 and 1.9 cm(2) V-1 s(-1), respectively.