A process for producing N-monosubstituted acrylamides in high yields without forming by-products. The process comprises preparing a .beta.-dialkylamino-(methyl)propionic ester by the reaction of a (meth)-acrylic ester with a specified dialkylamine, converting the formed ester into an N-monosubstituted .beta.-dialkylamino(methyl)propionamide by the reaction thereof with a primary amine in the presence of sodium methoxide, and thermally decomposing the amide under a reduced pressure.