The paper discusses the conceptual and methodological challenges of developing measures of stereotypes and prejudice for use in Slovakia. Developing these measures was the first step in a research project aimed at testing the effectiveness of direct and indirect contact interventions to reduce prejudice against stigmatized minorities, particularly the Roma. The first major problem in this kind of research relates to measuring the impact of interventions, as standardized instruments for measuring prejudice have yet to be developed in Slovak. The second (...) problem concerns the risk that the interventions will fail to reduce anti-Roma prejudice, because of the strong stigmatization of the Roma minority in Slovakia. The paper also reviews existing measures of stereotypes and prejudice in social psychology and discusses their applicability for measuring anti-Roma prejudice in Slovakia. It is argued that measures of stereotypes and prejudice should be designed and used in a sensitive manner and that in the process of measuring various forms of social bias we should avoid reproducing its cognitive, emotional and behavioural manifestations. (shrink)