Advances in genetic research have provided a basis for susceptibility testing for Alzheimer disease (AD). Prior surveys have examined attitudes toward genetic testing for AD in hypothetical scenarios, but it is unclear what reasons would motivate people to seek testing in real-life situations. This study presents data from the first randomized trial to evaluate genetic susceptibility testing for asymptomatic adult children of people with AD. We examined (1) reasons endorsed as motivations for seeking testing, (2) demographic characteristics associated with these reasons, and (3) how these reasons related to the eventual decision to pursue testing. Eligible participants were 206 adult children of people with AD (mean age 53 years; 72% female; 93% white), 77.7% of whom (n = 160) went on to seek testing. Participants endorsed numerous reasons for seeking susceptibility testing (mean 7.2), encompassing a range of motivations. The most commonly endorsed reasons were as follows: (1) to contribute to research (93.9%), (2) to arrange personal affairs (87.4%), and (3) the hope that effective treatment will be developed (86.8%). Women strongly endorsed more reasons for seeking testing than men (p < 0.05). The best predictor of actual pursuit of testing was strong endorsement of the need to prepare family members for AD (odds ratio = 3.3, p < 0.01). Findings suggest that genetic susceptibility testing is of interest to individuals at risk for AD for a variety of reasons, even in the relative absence of available treatments.