An analysis of survey data on membership, pillarisation, voting behaviour and attitudes. Belgian society is traditionally portrayed as heavily pillarised, i.e. having a system of exclusive linkages between voluntary associations and political parties, resulting in the formation of a catholic, a socialist and a liberal 'pillar' within society. Recently, several authors have questioned the validity oft his model. Our survey of the Flemish population, however, shows that pillarisation is an enduring feature of Flemish society. Membership of voluntary associations, trade unions and health insurance organisations remains ideologically motivated, and shows a high degree ofconsistency in this respect. Integration into a 'pillar' exerts a strong influence on voting behaviour, although this effect weakens in younger generations. Pillars also have significant, but weaker effects on attitudes like individualism, trust and solidarity. In the social capital research tradition, these differential effects of membership are often neglected. Although there are signs that pillarisation weakens in Fiemish society, the system certainly has not disappeared.