Germanium diselenide is an inorganic compound, with the chemical formula of GeSe2.

Germanium diselenide is prepared by reacting stoichiometric amounts of germanium and selenium or by reacting germanium tetrachloride with hydrogen selenide:[1] Germanium diselenide reacts with selenium and hydrazine to obtained yellow (N2H5)4Ge2Se6, a selenidogermanate.

[2] It reacts with lead selenide and gallium(III) selenide at high temperatures to obtain PbGa2GeSe6.

[3]