Conformation of 2-iminomethylthiophenes and of the 2,5-bis(methyliminomethyl)thiophene has been elucidated from theoretical investigations, dipole moment measurements, use of stereospecific coupling through five bonds, as well as Overhauser effect experiments. Only one conformation has been found: (2ctrans) for the 2-iminomethyl thiophenes and (2c 5ctrans) for the 2,5-bis(methyliminomethyl)thiophene. Keywords: thiophene, imine, conformation.