Six new aminoalkylsulfanyl polythiophenes (PTs), namely PTNHBoc, PTNMeBoc, PTNH2, PTNHMe, PTNMe2, and PTN+Me3, were synthesized. Four of them were obtained through Stille coupling, whereas PTNH2 and PTNHMe were obtained through deprotection via N-Boc precursors. The solubility changes going from the protected amines to the quaternary ammonium salt. All the polymers are soluble in DMSO and DMF. PTNHBoc and PTNMeBoc are also soluble in CHCl3, CH2Cl2, THF, and DMPU; PTNH2 and PTNHMe are soluble in CH3OH, whereas PTNMe2 and PTN+Me3 are soluble both in CH3OH and in H2O. These PTs show a tendency toward microaggregation in solution that does not represent an obstacle to their solubility. NMR, UV-vis, and XRD results prove that they are able to reach very high conjugation lengths and ordered conformations, not only in the solid state but also in solutions of good solvents.