The electronic and magnetic properties of Cr-, V-doped, and co-doped ZnSe in the wurtzite structure have been calculated within LSDA + U method. The ab-initio calculations are carried out using Atomistic ToolKit code, based on the density functional theory. The band structure and density of states calculations showed the half-metallic behavior for 12.5%, 6.25%, 3.125%, 1.5625% concentrations in ZnSe:Cr, ZnSe:V and ZnSe:Cr,V. The magnetic moments of Zn1-xCrxSe and Zn1-xVxSe supercells are 4 and 3 μB, respectively. Co-doping greatly raises the ferromagnetism and the value of total magnetic moment of the supercell is 7 μB. The defect formation energies were calculated and obtained that ferromagnetic state is more stable than antiferromagnetic state. The Curie temperatures are estimated for Zn1-xCrxSe and Zn1-xVxSe supercells for all studies concentrations. The results indicate that these materials are high Curie temperature DMSs. First-principles studies show that Cr- and V-doped ZnSe are promising materials for spintronics.