Memory is of fundamental importance for cognitive, social, and educational function, making it a target for neuropsychological assessment. The subject of this review is one particular type of memory, namely, episodic memory of unique events and experiences. Episodic memory allows for rapid, even one-trial learning of new information and retention of it for later retrieval. It depends on a particular neural substrate that undergoes a protracted developmental course. The review features discussion of some of the challenges associated with valid assessment of this specific form of memory in the preschool period, as well as a description and critical evaluation of available standardized measures. It also features description of two new approaches to assessment of episodic memory and their sensitivity to memory-specific deficits in the preschool years and in infancy. The review ends with introduction of the NIH Toolbox Picture Sequence Memory Test, designed as a measure of episodic memory in the preschool years and beyond.