Developmental trajectories of two classes of human memory, implicit and explicit memory, appear to diverge. We examined how developmental differences in perceptual and conceptual priming, two types of implicit memory, coincide with differences between familiarity and recollective responses on explicit memory tests that employ the Remember/Know paradigm ( Tulving, 1985 ). Both types of priming were characterized by developmental invariance in 52 children and adolescents ages 8-19 years. Contrary to Komatsu, Naito, and Fuke (1996) results, few age-group differences in perceptual priming were observed following a levels-of-processing encoding manipulation. In contrast, age group differences were found for "Remember" but not "Know" responses. Neither levels of awareness nor strategies influenced priming. Adult levels of performance appear earlier in development on perceptual and conceptual priming tests compared to explicit memory tests. Similar developmental dissociations exist between explicit and implicit memory performance as between "Remember" and "Know" recollective responses.