The crystal structure of 1-allyl-5-(4-methylbenzoyl)-4-(4-methylphenyl)pyrimidine-2(1H)-thione (C22H2oN2OS) has been determined from three dimensional single crystal X-ray diffraction data. The title compound crystallizes in the monoclinic space group P2(1)/c, with a = 10.6674(13), b = 10.1077(7), c = 17.9467(19) angstrom, beta = 98.460(9)degrees, V = 1914.0(3) angstrom(3), D-calc = 1.251 g cm(-3), Z = 4. In the title compound, the allyl group shows positional disorder. Molecules are linked by C-(HO)-O-..., C-(HN)-N-... and C-(HS)-S-... intermolecular interactions forming two-dimensional network. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA.