The present article analyzes trust in public institutions. In both theoretical literature and empirical research, a link between social trust and institutional trust has been established. The present paper casts additional light on this relationship. Moreover, it tests whether institutional trust is dependent on citizens’ perceptions of how well institutions live up to normative expectations held by the public. The focus on such normative expectations as incorruptibility and honesty is different from much of the previous empirical work which often predominantly focuses on policy outputs, such as economic performance, as a determinant of political support. Two main hypotheses derived from the theoretical discussion are tested in the analysis. H₁: Generalized social trust is positively associated with institutional trust.H₂: Perceptions of the capacity of institutions live up to such normative expectations as incorruptibility and honesty effect the extent to which they are trusted. Utilizing data from the European Social Survey, the analyses are first carried out at a country level and later at an individual level. Even though the hypotheses are verified to a large extent, the most powerful determinant of institutional trust proves to be satisfaction with policy outputs. Institutional trust is in general associated with social trust as well as with the perception that public officials act honestly, and the pattern is similar regarding trust in both parliament and the legal system. Further, the analysis suggests that the societies’ average levels of social trust and corruption do not affect the causal mechanisms of institutional trust at the individual level.