The electronic structures, magnetic properties, half-metallicity, and mechanical properties of half-Heulser compounds CoCrZ (Z=S, Se, and Te) were investigated using first-principles calculations within generalized gradient approximation based on the density function theory. The half-Heusler compounds show half-metallic properties with a half-metallic gap of 0.15 eV for CoCrS, 0.10 eV for CoCrSe, and 0.31 eV for CoCrTe at equilibrium lattice constant, respectively. The total magnetic moments are 3.00μB per formula unit, which agrees well with the Slater–Pauling rule. The half-metallicity, elastic constants, bulk modulus, shear modulus, Pough’s ratio, Frantesvich ratio, Young’s modulus, Poisson’s ratio, and Debye temperature at equilibrium lattice constant and versus lattice constants are reported for the first time. The results indicate that the half-Heulser compounds CoCrZ (Z=S, Se, and Te) maintain the perfect half-metallic and mechanical stability within the lattice constants range of 5.18–5.43 ? for CoCrS, 5.09–5.61 ? for CoCrSe, and 5.17–6.42 ? for CoCrTe, respectively.