Metastable　wurtzite-type　(gamma)　manganese　sulfide　(MnS)　crystallites　were　obtained　by　the　reaction　between　manganese　acetate　and　thioacetamide　under　the　microwave　irradiation　in　dilute　aqueous　ammonia　within　20　min.　The　samples　were　characterized　by　X-ray　diffraction　(XRD)　and　scanning　electron　microscope　(SEM).　It　shows　that　the　reaction　time　and　the　additive　tri-ethanolamine　(TEA)　play　the　important　role　in　eliminating　MnOx　impurities　and　favoring　the　formation　of　gamma-MnS.　(c)　2004　Elsevier　B.V.　All　rights　reserved.