Ammonium tetrathiotungstate is a chemical compound with the chemical formula (NH4)2WS4.

[3][4] Ammonium tetrathiotungstate can be obtained by the reaction of tungstic acid, ammonia, and hydrogen sulfide in a water bath at 65-70°C:[5] Ammonium tetrathiotungstate forms yellow to orange crystals, soluble in water.

[6][7] The compound decomposes under heat to produce tungsten trisulfide at 170-280°C and tungsten disulfide at 260-500°C.

[8] The compound is used in materials science and catalysis.

[7]