The present study examined individual differences in everyday cognitive failures assessed by diaries. A large sample of participants completed various cognitive ability measures in the laboratory. Furthermore, a subset of these participants also recorded everyday cognitive failures (attention, retrospective memory, and prospective memory failures) in a diary over the course of a week. Using latent variable techniques the results suggested that individual differences in cognitive abilities (i.e., working memory, attention control, retrospective memory, and prospective memory) were related to individual differences in everyday cognitive failures. Furthermore, everyday cognitive failures predicted SAT scores and partially accounted for the relation between cognitive abilities and SAT scores. These results provide important evidence for individual differences in everyday cognitive failures as well as important evidence for the ecological validity of laboratory cognitive ability measures. (Contains 6 tables and 6 figures.)