On the basis of the research literature, five aspects of the extreme right-wing ideology were distinguished: racism, extreme ethnic nationalism, the preference for a strong leadership, anti-parliamentarianism, and an anti-left attitude. The data of a postal survey in the spring of 1991 of a representative sample of the Flemish population in Belgium show that the items with which these extreme right-wing topics were operationalized show a one dimensional structure. About 10% to 25% of the interviewees agree with the individual items and about 20% of the subjects scored on the extreme right-wing side of the scale. The 'hardcore' of extreme right-wing respondents is, however, much smaller (about 1% to 2%), and does not seem to be higher in Flanders than in most of the surrounding countries. The right-wing extremism scale developed correlates as expected with a previously developed typology that integrates the attitude with respect to autochthons and allochthons. The analysis confirms that the voters for the Vlaams Blok - taken as a whole - may not be considered right-wing extremists, as suggested by previous research. Right-wing extremism correlates with a large number of attitudes and seems to be embedded in the broader opinion dimension of socio-cultural conservatism. This may also explain why it is associated primarily with the age, educational level, and religiosity of the respondents.