The title compound with systematic name: (S)-5-secbutyl-2-thiohydantoin, is synthesized through a solvent-free reaction, crystallizes in the non-centrosymmetric space group P2(1)2(1)2(1). In the crystal structure, the molecules are joined by N-H center dot center dot center dot O and N-H center dot center dot center dot S hydrogen bonds, forming chains C-2(2)(10) and macrocycles R-6(5)(26) in an infinite bi-dimensional network.