In the title compound, C(9)H(20)N(2)S, the n-butyl groups are in syn and anti positions in relation to the C=S bond. In the crystal, two mol-ecules are connected by two N-H⋯S=C hydrogen bonds into a centrosymmetric dimer. Another N-H⋯S=C hydrogen bond links the dimers, forming layers with a hydro-philic inter-ior and a hydro-phobic exterior, which spread across the (100) plane. Inter-lacing of the external butyl groups combines these layers into a three-dimensional structure.