A novel pyrene containing thiophene monomer 3-methyl-4-(4-(pyren-1-yl)butoxy) thiophene was synthesized and fully characterized by FTIR and 1 H and 13 C NMR spectroscopies. This monomer was polymerized and copolymerized in the presence of 3-methyl-4-(tetraethoxy) thiophene, 3-hexylthiophene, 3-decylthiophene, and 3-dodecylthiophene using FeCl 3 as oxidizing agent, to give the corresponding homopolymer HP3 and copolymers (CP1, CP2, CP3, CP4,CP5 and CP6). These polymers exhibited good thermal stability with T 10 values between 312 and 414°C, and T g values varying from −38 to 24°C. CP5 exhibited two absorption bands at 246 and 416nm whereas CP6 absorbed only at 242nm. The emission spectra of both polymers showed a monomer emission at 376–396 followed by an intense excimer emission at 570nm, which reveals the presence of intramolecular non parallel pyrene–pyrene interactions.