 Metaethical constructivist theories aim to account for the nature of normative truths and practical reasons. They bear a problematic relation to traditional classifications of metaethical theories. In particular, there are disagreements about how to situate constructivism in the realism/antirealism debate. These disagreements are rooted in further differences about the definition of metaethics, the relation between normative and metaethical claims, and the purported methods pertinent and specific to metaethical inquiry. The question of how to classify metaethical constructivism will be addressed in what follows by focusing on the distinctive questions that constructivist theories have been designed to answer. Section 1 explains the origin and motivation of constructivism. Sections 2–4 examine the main varieties of metaethical constructivism. Section 5 illustrates related constructivist views, some of which are not proposed as metaethical accounts of all normative truths, but only of moral truths. Sections 6 and 7 review several debates about the problems, promise and prospects of metaethical constructivism.