Solution-processed organic or organic-inorganic hybrid photovoltaic devices possess many advantages both in the commercial manufacture and daily operation, thus becoming competitive candidates of the next generation solar cells. To exert these advantages, this review summarizes the recent progresses in creating organic-inorganic hybrid solar cells, and in particular polymer-nanocrystals hybrid solar cells via aqueous-solution-processed approaches. The basic principles of the hybrid photovoltaic devices are illustrated first, which are essential for the effective photoelectric conversion. Then we focus on the achievement of the aqueous hybrid solar cells and the limiting factors of the power conversion efficiency (PCE). On this basis, different aqueous-solution-processed methods and the efforts to improve the PCE are presented in detail. Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.