In the title compound, [Ni(NCS)(2)(C(6)H(10)N(2))(4)]·C(6)H(10)N(2), the asymmetric unit comprises a Ni(II) complex and a co-crystallised mol-ecule of 3,4,5-trimethyl-1H-pyrazole (PzMe(3)). The Ni(II) atom is coordinated by four PzMe(3) mol-ecules and two thio-cyanate anions to define a trans N(4)S(2) distorted octa-hedral geometry. A number of intra-molecular N-H⋯N, N-H⋯S and C-H⋯N inter-actions contribute to the stability of the complex. The crystal structure is stabilized by inter-molecular N-H⋯S inter-actions, which link neighbouring mol-ecules into chains along the a axis.