Objective: Searching the Internet for health-related information is a complex and dynamic goal-oriented process that places demands on executive functions, which are higher-order cognitive abilities that are known to deteriorate with older age. This study aimed to examine the effects of older age on electronic health (eHealth) search behavior, and to determine whether executive functions played a mediating role in that regard. Method: Fifty younger adults (≤ 35 years) and 41 older adults (≥50 years) completed naturalistic eHealth search tasks involving fact-finding (Fact Search) and symptom diagnosis (Symptom Search), a neurocognitive battery, and a series of questionnaires. Results: Multiple regression models with relevant covariates revealed that older adults were slower and less accurate than younger adults on the eHealth Fact Search task, but not on the eHealth Symptom Search task. Nevertheless, executive functions mediated the relationship between older age and eHealth Fact Search and Symptom Search accuracy. Conclusions: Older adults can experience difficulty searching the Internet for some health-related information, which is at least partly attributable to executive dysfunction. Future studies are needed to determine the benefits of training in the organizational and strategic aspects of Internet search for older adults and whether these findings are applicable to clinical populations with executive dysfunction.