Tolerance of political opponents is one of the basic preconditions of a democratic society. Empirical research, however, typically reveals low levels of tolerance even in societies with long democratic tradition. This paper presents a comparative study of the sources of individual differences in the degree of political tolerance in Europe, with special reference to Serbia. According to Sullivan et al.'s theory (Sullivan et al. 1979, 53-55), socio-demographic factors are decisive for the choice of a group towards which the intolerance will be directed, while psychological factors are more important for the level of intolerance. Implications of this theory are examined using data collected in about 30 European countries. The research is based on World Values Survey data (WVS). The WVS data include the so-called 'least- liked' operationalization of political intolerance. The findings reveal significant impact of psychological factors on the target group selection, and not only on the degree of intolerance, contrary to Sullivan et al.'s theory.