In this study 4-(3-coumarinyl)-3-benzyl-4-thiazolin-2-one 4-methylbenzylidenehydrazone 3 was synthesised. An independent proof of the thiazolylhydrazone structure of 3 was achieved by single crystal X-ray diffraction analysis. Elemental analyses and spectral data (IR, H-1-NMR, C-13-NMR and EIMS) of 3 was also determined. The coumarin ring system and the thiazole ring are almost planar, the dihedral angle between them is 62.93(5)degrees. The phenyl groups make dihedral angles of 86.09(7) and 31.67(7)degrees with the thiazole ring plane. The crystal structure is stabilised. by intra-, intermolecular hydrogen contacts and C-H....pi type interactions.