Oximinophosphoric acid derivatives of the formula ##STR1## where R.sup.1 is straight-chain or branched alkyl of not more than 4 carbon atoms, R.sup.2 is a straight-chain or branched alkoxy or alkylthio group of not more than 4 carbon atoms, straight-chain or branched alkyl or not more than 3 carbon atoms, phenyl, amino or a straight-chain alkylamino or dialkylamino radical where alkyl in each case is of not more than 4 carbon atoms, R.sup.3 is methyl or ethyl and X is oxygen or sulfur, a process for the manufacture of these oximinophosphoric acid derivatives of the formula I, and their use as pesticides.