Aims: We investigated whether the longitudinal relation between memory complaints and subsequent decline in executive functioning over 6 years differed by leisure activity engagement as major contributor to cognitive reserve in old age. Methods: We analyzed longitudinal data from 897 older adults (M = 74.33 years) tested on the Trail Making Test (TMT) in two waves 6 years apart. Participants reported information on memory complaints and leisure activity engagement. Results: There was a significant interaction of memory complaints with leisure activity engagement on latent change in executive functioning. Specifically, only for individuals with less (but not those with greater) leisure activity engagement, memory complaints significantly predicted a steeper subsequent decline in executive functioning across 6 years (i.e., increases in TMT completion time). Conclusion: The role of memory complaints as an early predictor of decline in executive functioning seems to vary by individuals' cognitive reserve.