A process for preparing fluorochemical monoisocyanates comprises reacting at least one fluorochemical alcohol represented by the formula CnF2n+1SO2NCH3(CH2)mOH, wherein n=2 to 5, and m=2 to 4, with 4,4′-diphenylmethane diisocyanate (MDI) in a solvent in which the resulting fluorochemical monoisocyanate is not soluble; wherein the molar ratio of fluorochemical alcohol:MDI is from about 1:1 to about 1:2.5.