Hetero-tetrahydroquinolines can be prepared either by condensing correspondingly substituted hetero-tetrahydroquinoline aldehydes with the desired substituent or by reducing the corresponding keto-substituted hetero-tetrahydroquinolines, followed by introduction of the desired substituent by customary methods. The hetero-tetrahydroquinolines are suitable for use as active compounds in medicaments, in particular in medicaments for treating artheriosclerosis and dyslipidaemias.