2-(1,2,4-Oxadiazol-5-yl)vinylphosphates and 2-(1,2,4-thiadiazol-5-yl) vinylphosphates are prepared from the corresponding chlorophosphates and 5-acetonyl-1,2,4-oxadiazoles and 5-acetonyl-1,2,4-thiadiazoles resp. Some of the oxazolylvinylphosphates are effective insecticides and acaricides, but the corresponding thiadiazole derivatives have almost no effect.