Recent protests on the persisting influence of Belgium’s colonial past on contemporary society begs the question as to how we should understand the recent social movement around decolonization. Current research into postcolonial issues is predominantly qualitative and text-based. This research, however, takes a quantitative approach to investigate widely held attitudes among citizens. In doing so, it maps the attitudes in Belgian public opinion concerning decolonization measures relying on a representative survey conducted among the Belgian population (N = 1026). Based on attitudes of Belgian respondents, we propose a conceptual distinction between additive measures (whenever an addition is being made) and subtractive measures (which implies a removal). The data shows that there is no polarization on this issue in Belgium, but that the majority of the respondents are willing to support decolonization measures. Three sets of hypotheses on the effects of knowledge, age, and party preference are tested to examine these attitudes. Both knowledge and party preference have a significant influence on the support for decolonization in general, while age only has a significant effect for subtractive measures. The implication of this research is that there is a need for a dialogue between different approaches to study decolonization.