The synthesis of azathia analogues of the platelet activating factor with oxygen and sulphur-containing sidechains is reported. The starting point is 1-acetylthio-3-hydroxy-2-propaneamine-HCl, which permits the formation of the thioether and the acetamido linkage in one step. The phosphocholine part is introduced via 2-chloro-2-oxo-1,3,2-dioxaphospholane and subsequent ring opening with trimethylamine under pressure.