Abstract: A process for the preparation of an N-(.alpha.-alkoxyethyl)carboxylic acid amide represented by the following formula [I]: ##STR1## wherein R stands for a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a benzyl group or an aryl group, and R.sup.1 stands for an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group,which comprises reacting an ethylidene-bisamide represented by the following formula [II]:CH.sub.3 CH(NHCOR).sub.2 [II]wherein R stands for a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a benzyl group or an aryl group,with an alkanol in the presence of an acid catalyst. According to this process, a high-purity N-(.alpha.-alkoxyethyl)carboxylic acid amide, which is valuable as an intermediate for the production of an N-vinylcarboxylic acid amide and the like, can be easily prepared from cheap and easily available starting materials.