Cubic　ZnIn2S4　nanoparticles　and　hexagonal　ZnIn　2S4　flower-like　microspheres　were　controlled　synthesized　via　a　facile　hydrothermal　method　by　simply　changing　the　metal　precursors.　The　as-prepared　samples　were　characterized　by　XRD,　SEM,　TEM　and　UV-vis　DRS.　It　was　found　that　the　metal　precursors　influenced　the　final　ZnIn2S　4　polymorphs,　i.e.,　metal　nitrates　led　to　the　formation　of　cubic　ZnIn2S4,　while　metal　chlorides　resulted　in　the　formation　of　the　hexagonal　phase.　The　formation　processes　of　the　cubic　ZnIn　2S4　nanoparticles　and　hexagonal　ZnIn2S　4　flower-like　microspheres　were　investigated　and　the　mechanism　of　the　phase　formation　was　proposed.　Although　both　cubic　and　hexagonal　ZnIn　2S4　polymorphs　exhibited　photocatalytic　activity　for　the　degradation　of　methyl　orange　(MO)　under　visible　light　irradiation,　the　photocatalytic　performances　over　cubic　and　hexagonal　ZnIn2S　4　were　different.　©　2011　The　Royal　Society　of　Chemistry.