Abstract Ternary and quaternary chalcogenides are thought to be promising candidates for low cost and sustainable solar energy converting devices due to large extinction coefficient and ideal band gap energy. Among them, Cu 2 ZnSnS 4 (CZTS) is one of the most important materials because of its earth-abundant as well as non-toxic elements. In this report, by choosing suitable surfactant and sulfur source, CZTS nanocrystals with wurtzite crystal structure are synthesized by using one-pot reaction in aqueous phase. The obtained water soluble nanocrystals exhibit a band gap of 1.43 eV and show promising photoresponse under illumination of light source, suggesting their potential in the field of optoelectronic devices.