Building on longitudinal findings of linkages between aspects of teachers' language during instruction and children's use of mnemonic strategies, this investigation was designed to examine experimentally the impact of instruction on memory development. First and second graders (N = 54, Mage = 7 years) were randomly assigned to a science unit that varied only in teachers' use of memory‐relevant language. Pretest, posttest, and 1‐month follow‐up assessments revealed that although all participating children learned new information as a result of instruction, those exposed to memory rich teaching exhibited greater levels of strategic knowledge and engaged in more sophisticated strategy use in a memory task involving instructional content than did students exposed to low memory instruction. The findings provide support for a causal linkage between teachers' language and children's strategic efforts.