The Internet has become a major health information source for many patients, and they might discuss the information they get from the Internet with their doctors. I explored how the Internet as an information source influences cancer patients' communication with their doctors in Taiwan, where the doctor-patient relationship is traditionally doctor dominated. Forty-six cancer patients or families participated in seven focus group discussions. I conducted inductive analysis to examine themes emerging from discussions. Participants searched for information on the Internet to probe and verify their doctors' competence. Participants took responsibility for understanding the doctors' jargon, and the Internet helped them to do that. The Internet also helped participants spur doctors to think further about their condition, but these patients did so cautiously, with an effort not to offend doctors. The Internet as an information source did help participants talk to doctors, but the effect on changing the doctor-dominant nature of the relationship was limited.