Abstract <p>The temperature dependence of the specific electrical resistivity of the high-entropy equiatomic CoCrFeNi alloy was studied in the range of 1100–1900 K using the contactless rotating magnetic field method, including the solid and liquid states. It was found that the electrical resistivity increases linearly with temperature, and at the melting point, there is an abrupt change toward an increase in its value. High absolute electrical resistivity values and a low temperature coefficient of about 10^–4 K^–1 are retained in the condensed state. The temperature dependence of electrical resistivity obeys the Bloch–Grüneisen law, and the main scattering mechanism at high temperatures is associated with the defect crystal lattice and, to a lesser extent, with phonons. The behavior of the electrical resistivity of the disordered solid solution CoCrFeNi at high temperatures confirmed that the conductivity was metallic type.</p>