Schools are expected to educate children into democratic citizens by providing "civics" or history courses. It is believed that the formal curriculum affects the amount of cognition of each pupil, which - in its turn - would influence the civic competencies and social attitudes. This supposition is explicitly stated in 'holocaust-education 'programs and in 'civics'-courses. Accordingly, knowledge on the nazi-attrocities would stimulate tolerance, and by this way counter prejudice. The current contribution tests this supposition on survey-data (2002) from 773 Frenchspeakin g and 469 Flemish-speaking last-grade pupils from secondary schools in the Brussels-Capital Region. The survey probed for knowledge on the nazi-genocide and attitudescales (ethnocentrism and anti-democracy). The supposition about the connection between knowledge and tollerance, holds partially for the Flemish, but not for the French-speaking sample. Knowledge may be a necessary, but is certainly nota sufficient condition to foster tolerance.