Combattting fungi and bacteria with aminomethylheterocyclic compounds of the formula ##STR1## in which R.sup.1 represents hydrogen, alkyl, alkenyl, in each case optionally substituted tetrahydronaphthyl, decahydronaphthyl, cycloalkyl or cycloalkenyl, furthermore alkyl which is substituted by cycloalkyl, cycloalkenyl, cycloalkyloxy or cycloalkylthio, where the cyclic radicals may optionally be substituted, furthermore optionally substituted aryl, in addition alkyl which is substituted by aryl, aryloxy, arylthio, arylsulphinyl or arylsulphonyl, or alkenyl which is substituted by aryl, where the aryl radicals may in each case optionally be substituted;R.sup.2 represents hydrogen or methyl,R.sup.3 represents alkyl, alkenyl, alkinyl, alkoxyalkyl, hydroxyalkyl, hydroxyalkoxyalkyl, dialkoxyalkyl, or in each case optionally substituted cycloalkyl, cycloalkylalkyl, aryl, aralkyl, aralkenyl, furanylalkyl, tetrahydrofuranylalkyl, tetrahydropyranylalkyl, dioxolanylalkyl or dioxanylalkyl, andX represents oxygen, sulphur or a CH.sub.2 group,or acid additon salts thereof. Many of the compounds wherein R.sup.1 has a narrower meaning are new.