Language function in patients with impaired declarative memory presents a compelling opportunity to investigate the inter-dependence of memory and language in referential communication. We examined amnesic patients' use of definite references during a referential communication task. Discursively, definite references can be used to mark a referent as situationally unique (e.g., "the game," as in the case of a recently publicized game) or as shared information (e.g., "the game," as in one discussed previously). We found that despite showing normal collaborative learning after repeated referring-as indexed by consistent and increasingly efficient descriptive labels for previously unfamiliar tangram figures-amnesic patients did not consistently use definite references in referring to those figures. The use of definite references seems to be critically dependent on declarative memory, and the engagement of such memory is signaled by language.