The invention relates to amphiphilic acetal of the formula (1) ##STR00001## wherein R.sup.1 is n-C.sub.8-C.sub.22-alkyl, iso-C.sub.9-C.sub.22-alkyl, n-C.sub.5-C.sub.18-alkylphenyl or iso-C.sub.5-C.sub.18-alkylphenyl, R.sup.2 and R.sup.4 are each independently C.sub.1-C.sub.7-alkyl or have the same meaning as R.sup.1, R.sup.3 is C.sub.1-C.sub.7-alkyl, A is a group of the formulae --C.sub.2H.sub.4-- or --C.sub.3H.sub.6--, and the indices a, b, c and d are each independently from 0 to 50, where at least one of the indices a, b, c or d has to have a value other than 0. The compounds of the invention are suitable as surfactants, emulsifiers, demulsifiers, humectants, foamers, or antifoaming agents.