This article reports an investigation on the cognitive and linguistic mechanisms involved in knowledge management during discourse production of individuals with Alzheimer disease (AD). Two discourse variables were examined, incomplete propositions and repeated propositions. Differences between controls and participants with AD were found concerning the presence of incomplete propositions in a non-informative prompted task. Findings obtained with the informative prompted task suggested that knowledge management was more preserved in the early stage than in the later stage of AD. The majority of the neuropsychological data obtained in this study correlated with the presence of incomplete propositions. The discussion debated on whether this discourse deficit can be attributed to an impaired ability to manage knowledge provided in the context of communication.