Germanium(II) iodide can be produced by reacting germanium(IV) iodide with hydriodic acid and hypophosphorous acid and water:[1] It can also be formed by the reaction of germanium monosulfide or germanium monoxide and hydrogen iodide.

[1] It can also be produced from the direct reaction of germanium and iodine at 200 – 400 °C:[1] Germanium(II) iodide can also be formed from the decomposition of HGeI3, which can be prepared by reacting HGeCl3 with hydroiodic acid:[5] Germanium(II) iodide is a yellow crystal that slowly hydrolyzes into germanium(II) hydroxide in the presence of moisture.

It is insoluble in hydrocarbons and slightly soluble in chloroform and carbon tetrachloride.

[6] Germanium(II) iodide can react with carbene to form stable compounds.

[2] It is also used in the electronics industry to produce germanium layers epitaxially through disproportionation reactions.