Breast cancer is the most common form of cancer found among women in the United States. During the course of the illness, women diagnosed with breast cancer need information and support to cope with the illness. To understand what leads women with breast cancer to consult the Internet for health-related information, we examined how unmet needs-needs that have not been satisfied-in regards to information and emotional support determine patterns of cancer patients' health-related Internet use. Using data collected from 122 women diagnosed with breast cancer, we found that the higher the unmet need for information was, the more likely individuals were to spend time in specialized health information. Likewise, the higher the unmet need for emotional support was, the more likely individuals were to spend time in social support services such as discussion groups. Implications for future research on unmet needs and the use of the Internet were discussed.