Patients may bring unreliable information to the physician, complicating the physician-patient relationship, or outside information seeking may complement physician information provision, reinforcing patients' responsibility for their health. The current descriptive evidence base is weak and focuses primarily on the Internet's effects on physician-patient relations. This study describes how cancer patients bring information to their physicians from a range of sources and are referred by physicians to these sources; the study also examines explanations for these behaviors. Patients with breast, prostate, and colon cancer diagnosed in 2005 (N = 1,594) were randomly drawn from the Pennsylvania Cancer Registry; participants returned mail surveys in Fall 2006 (response rate = 64%). There is evidence that both bringing information to physicians and being referred to other sources reflects patients' engagement with health information, preference for control in medical decision making, and seeking and scanning for cancer-related information. There is also evidence that patients who bring information from a source are referred back to that source.