A largely preserved cognition is a prerequisite for everyday-life functioning and wellbeing in old age. In this study we evaluate birth cohort differences as a contextual factor for level and rate of cognitive change from age 70 to 79 based on comparisons of two age-homogenous birth cohorts born 30 years apart (i.e. in 1901-02 and 1930). Data was drawn from the Gerontological and Geriatric Population Studies in Gothenburg, Sweden (H70, N=1176) including three repeated follow-up measures using a similar cognitive battery at each occasion. Our main finding, in line with previous reports is that of a substantial increase in average performance across cognitive measures in favor of the later born cohort. However, the 1930 born cohort also exhibited a tendency toward a steeper average rate of decline. Further evaluation of moderating and mediating effects of birth cohort differences in cognitive functioning will be discussed. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved.