The authors examined the long-term cognitive implications of cancer treatment among breast cancer survivors over 65 years old who received treatment during midlife. Thirty women survivors were matched with 30 noncancer, healthy older adults in terms of age, education, and IQ. The cancer survivors scored significantly lower in the cognitive domains of executive functioning, working memory, and divided attention, reflecting potential dysfunction in frontal-subcortical brain regions. Our findings suggest that among breast cancer survivors who remain disease-free for more than a decade, the previous cancer treatment may further augment cognitive dysfunction associated with age-related brain changes.