The Danes have traditionally seen themselves as an enlightened and tolerant people, regarding with contempt those who, like many white Americans or South Africans, hold negative attitudes towards ethnic or racial minorities. This positive self-image was confirmed during World War II when in an impressive rescue operation almost all Danish Jews (the only sizeable minority group in Denmark at the time) were helped to safety in neutral Sweden. During the 1960s and 1970s Danish society - until then one of the most homogeneous societies in Europe - became increasingly more heterogeneous through the influx of economic migrants - ‘foreign workers’ - mainly from Turkey, Pakistan and Yugoslavia. For the first time the Danes have had to deal with ethnic minorities whose culture, language, religion and physical appearance differ significantly from the majority's. On the basis of a comprehensive attitude survey, it appears that the Danes today are less tolerant towards ‘foreign workers’ than might have been expected on the basis of their past record. This article considers whether this intolerance can be explained in terms of (1) the structure of present-day Danish society; (2) the general characteristics of the respondents (age, gender, etc.), or (3) the social and cultural characteristics of the new minorities. It is suggested that ethnic prejudice exists latently even in apparently tolerant societies and tends to surface when a 'suitable’ target group becomes available.