Potassium tetraiodoplatinate is the inorganic compound with the formula K2PtI4·(H2O)2.

It is the potassium salt of tetraiodoplatinate, a square planar complex of platinum(II).

The compound crystallizes from water as the dihydrate,[1] whereas the related chloride and bromide K2PtCl4 and K2PtBr4 are obtained only as the anhydrous salts.

It reacts with amines and with ammonia to give charge-neutral derivatives PtI2(RNH2)2.

[2] The compound is prepared by the salt metathesis reaction of potassium iodide and potassium tetrachloroplatinate:[3] Potassium tetraiodoplatinate is a precursor to the anticancer drug cisplatin.