Electrochemical oxidation of chalcopyrite (CuFeS2) was investigated as an attempt to gain a better understanding of its surface oxidation chemistry in alkaline solutions. Rest potential measurements, cyclic voltammetry and chronoamperometry experiments were conducted in the pH range of 7 to 13 to determine the influence of pH, immersion time, and applied potential on the mineral oxidation state. Rest potential was found to increase by immersion time and oxygen content of the solution and decrease by the pH value. Cyclic voltammetry experiments revealed that the mineral oxidation occurs in three stages. Increase of the pH value caused the peaks to shift to lower potentials. The results were confirmed by chronoamperometry experiments.