Résumé : The tumultuous pedestrianisation of the city centre has been a fertile ground for observing both the new ways in which public authorities attempt to involve or rally citizens around a project, and the more diverse ways in which citizens(and even more-than-humanentities - trees, concrete, viruses, etc.) take part in and contributeto the progressive compositionof a part of the city. As a field for investigation and experimentation, pedestrianisation has not onlymade it possible to identify, amplify and bring out more inclusive and emancipatory forms of participation, it has also drawn out lessons for other places and cases in the Brussels-Capital Region, under the formula of “Learning from pedestrianisation”.Involving citizens in matters that concern them is at the heart of many of Brussels’ public policies. However, participation processes often leadto disappointment, frustrationand even disinterest for everyone involved. Citizens do not feel heard or do not see their opinions and contributions being acted upon; public authorities feel trapped by sometimes contradictory injunctions and needs that are impossibleto take into account. In light ofthis widespread complexity and disenchantment, the p-lab project aimed to give “participation” a better chance of unleashing its democratic and practical potential.