The past decade has seen a reconceptualization of explicit memory that closely links it with prospective cognition. This chapter provides a brief historical perspective on prospection within memory research, an overview of the major modes of prospective cognition, and a comprehensive review of research examining episodic and semantic contributions to future-oriented thinking. We consider taxonomic issues in this emerging subfield, as well as the factors that appear to modulate the degree to which episodic and/or semantic memory are involved in prospection, including contextual specificity and psychological distance, while emphasizing the notion that most prospective thoughts are hybrid representations comprising episodic details and multiple types of semantic knowledge.