This chapter introduces conversational recommender agents that facilitate user navigation through a product space, alternatively making concrete product suggestions and eliciting the user’s feedback. Critiquing is a common form of user feedback, where users provide limited feedback at the feature-level by constraining a feature’s value-space. For example, a user may request a cheaper product, thus critiquing the price feature. One of the most important objectives in a recommender agent is to discover, with minimal user feedback, which are the user’s product preferences. For this purpose, the chapter includes recent research on critiquing-based recommendation and a comparison between standard and recent proposals of recommendation based on critiquing.