n-CdTe/p-CuInSe2 heterojunctions were fabricated by flash evaporating p-CuInSe2 on indium-doped CdTe single crystals. I-V characteristics and the photospectral response of the heterojunctions were studied. On illumination appreciable change in the I-V characteristics and photovoltaic effects were observered. A theoretical energy-band diagram for the heterojunction was constructed, and the theoretical and experimental barrier potentials were compared.