Hydrogen overpotentials on pure Zn, Cd, Fe, and Pb were measured in 6N potassium hydroxide solution at 2°, 25°, and 50°C. Measurements were also made in 9N potassium hydroxide solution at room temperature. Exchange current densities, transfer coefficients, and heats of activation for the hydrogen solution process were obtained, and the mechanism for process in the solution is discussed. The transfer coefficients in the alkaline solutions are compared with these in acid solutions.