Abstract: This chapter evaluates the life-course determinants of cognitive functioning among 1,003 women and men of 50 years and older in Ismailia, Egypt. Three questions motivate this analysis: (a) Do older women have poorer cognitive functioning than older men? (b) Do cognitive resources accrued in childhood and adulthood have net positive associations with later-life cognitive functioning for women and men? and (c) To what extent do differences in the amounts and effects of women's and men's cognitive resources account for gaps in their cognitive functioning? The results show that, compared to older men, older women have lower Modified-Mini Mental Status Exam (M-MMSE) scores for overall cognitive functioning. Cognitive resources in childhood and adulthood are jointly associated with the M-MMSE score. About 83 percent of the gender gap in mean M-MMSE scores is attributable to gaps in men's and women's attributes across the life course. Gender gaps in childhood cognitive resources, and especially schooling attainment, account for the largest share (18 percent) of the gender gap in cognitive functioning.