Often, people are able to recall a message on a particular topic for a long period of time. These memorable messages have the ability to influence behavior when they are recalled from memory long after initial exposure. Knowing the topics and sources of the messages that are remembered about breast cancer can improve the efficacy of future breast cancer outreach. To this end, 359 women completed an online survey about memorable breast cancer messages. Most women (60%) recalled a memorable message, described it, identified its source, and noted whether it had resulted in prevention or detection behaviors. Four categories of message topics emerged: early detection (37.3%), awareness (30.9%), treatment (25.8%), and prevention (6%). Furthermore, five categories of sources of these memorable messages were found: media (35.5%), friends (22.2%), family (21.6%), medical professionals (15.2%), and others (5.5%). The media were a major source of all four topics of messages, although family members, friends, and the medical community were major sources for particular message topics as well. Memorable messages originating from medical professionals were substantially more likely to motivate detection behaviors than prevention behaviors. This research demonstrates that message topic and source both play roles in determining message recall as well as in determining how memorable messages impacted behavior.