In this introduction to The Development of Children’s Memory: The Scientific Contributions of Peter A. Ornstein, we provide biographical information for Professor Ornstein and identify some contextual influences on his work. We then examine the four distinct but interrelated programs of research he conducted that form the structure for this volume. Next, we briefly describe the chapters that are included in the review of each research program and introduce the authors. Ornstein’s scientific development over his 50 years in research is depicted as moving from the study of age-related changes in memory performance to an increasing emphasis on the developmental processes that result in skilled remembering in children. This transition both reflected and contributed to the emergence of a developmental science of memory.