This study examined the relationship between memory knowledge and peoples' perceptions of forgetful younger and older adults in two ways. First, using an experimental approach, younger and older research participants were assigned to one of three information conditions: control (received no information about memory and aging), grandparent (received information about grandparent-grandchild relationships), and memory aging (received information about normative age-related changes in memory functioning in later adulthood). One week later, participants read six vignettes describing fictitious persons experiencing everyday instances of forgetting who were either younger (23-35 years of age) or older (63-75 years of age). Following Erber, Szuchman, and Rothberg (1990a), participants rated the likelihood of six possible causes for the memory failures: ability, effort, task difficulty, luck, and two scales measuring attention (external and internal distractions). Participants also rated the degree to which: (a) the forgetting was a sign of mental difficulty, (b) the person should seek training to improve his/her memory, and (c) the person should seek medical and/or psychological evaluation for the forgetting. Participants made their evaluations on separate 7-point Likert scales. Contrary to expectations, the groups did not differ in perceptions of older forgetful persons; however, participants in the memory aging seminar group showed significant pre- to posttest gains on the Knowledge of Memory Aging Question (KMAQ; Cherry, West, Reese, Santa Maria, & Yassuda, 2000), indicating that the information presented increased knowledge of normal age-related memory changes. Second, individual differences in memory aging knowledge were analyzed by evaluating the relationship between pretest performance on the KMAQ and ratings on the causal attribution and memory opinion scales for participants in the two control conditions only (control and grandparent seminar participants). Contrary to expectations, but confirming findings from the experimental approach, pretest knowledge of normal age-related memory changes were not correlated with evaluations of forgetful individuals. Taken together these data suggest that perceptions of forgetfulness in older adults are not necessarily influenced by explicit knowledge of normative age-associated memory changes.