Article dans une revue: We use a non-Bayesian approach to uncertainty, where "ambiguity" is taken into account, in order to analyze the issue of central bank transparency, and we underline that the use of such an approach may greatly change the results. We reconsider a specific argument against transparency found in the literature. We show that, in the presence of ambiguity, the argument can become a case in favor of transparency, which seems more in accordance with some stylized facts. Reduced Knightian uncertainty associated with increased transparency can contribute to making transparency beneficial.