Aging is characterized by a decrease of cognitive performance in most of cognitive domains. One of the most fundamental issues is then to know what are the underlying mechanisms of these age-related changes in human cognition. Recent research suggests that in addition to speed of processing and working memory capacities, age-related impairment in executive functioning plays an important role in the cognitive decline associated to aging. Above and beyond performance, current research shows that the mediating role of executive function in age-related changes in cognitive performance occurs via changes in strategies variations (i.e., repertoire, distribution, execution, and selection of the strategies used to accomplish a cognitive task). In this article, we illustrate both strategic variations and underlying executive control mechanisms in two important cognitive domains : episodic memory and problem solving. (C) 2013 Societe francaise de psychologie. Published by Elsevier Masson SAS. All rights reserved.