We report on solution-processed hybrid solar cells consisting of a nanocrystalline inorganic semiconductor, CuInS2, and organic materials. Synthesis of quantized CuInS2 nanoparticles was performed using a colloidal route, where the particle surface was shielded by an organic surfactant. First attempts were made to use nanocrystalline CuInS2 with fullerene derivatives to form flat-interface donor–acceptor heterojunction solar cells. We investigated also bulk heterojunctions by replacing the CuInS2 single layer by a blend of CuInS2 and p-type polymer (PEDOT:PSS; poly(3,4-ethylenedioxythiophene:poly(styrene sulfonic acid) in the same cell configuration. Bulk heterojunction solar cells show better photovoltaic response with external quantum efficiencies up to 20 %.