A group of (carbamoylaminophenoxymethyl)-dimethylphosphine oxides 1-13 and corresponding thiocarbamoyl derivatives 14-26 were prepared via reaction of 2-, 3-and 4-(dimethylphosphinylmethoxy)-phenylamines with isocyanates and isothiocyanates resp. The composition of the new compounds was confirmed by elemental analysis, IR, H-1 and P-31[H-1] MNR spectroscopy.