The title compound, C13H12N2OS, was prepared by condensation of 4-methoxycinnamaldehyde and thioacetamide in ethanol at room temperature. Its investigation was undertaken as part of our search for new non-linear optical compounds. The pi-conjugated title molecule is almost planar, the dihedral angle between the central planar 2-cyano-5- (4-methoxyphenyl)penta-2,4-diene fragment and the thioacetamide group being 9.2 (6)degrees. Molecules are linked by N-H ... N and N-H ... O hydrogen bonds forming a two-dimensional motif.