Here we report the application of stable stannite phase CuZn2AlS4 (CZAS) nanocrystals (NCs), prepared by using a facile hydrothermal approach, as electron acceptor and photo-active material in organic-inorganic hybrid solar cells, for the first time. The photovoltaic (PV) performance of devices have been investigated in both inverted and classical device architectures with Poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and Poly(3-hexylthiophene-2,5-diyl) (P3HT) electron donor materials. First, PV devices of inverted architectures have been fabricated using MEH-PPV and CZAS NCs and their blending ratio has been optimized for optimum power conversion. Furthermore, devices of classical architecture have been also fabricated using optimized ratio of the CZAS NCs. A significant improvement in device efficiency has been observed on blending CZAS NCs in photoactive layer. Devices without CZAS NCs exhibited 1.72% whereas on incorporation of CZAS NCs 3.25% device efficiency has been observed.