The synthesis and crystal structures of the ternary uranium compounds UYX, where Y = Si, Ge, Sn, Sb, and X = S, Se, Te, are reported. USiS, UGeS, USnTe, USbS, USbTe and also UTe2 - x are isotypic with ZrSiS which has a distorted PbFCl-type structure. USiSe, UGeSe and UGeTe have structures of a new type, closely related to that of ZrSiS. The compounds USiTe, USnS and USnSe could not be prepared. The instability of these compounds and the occurence of ZrSiS and UGeTe-type compounds are discussed. © 1969.