Background: The U.S. Institute of Medicine recommends that cancer patients receive survivorship care plans, but evaluations to date have found little evidence of the effectiveness of such plans. We conducted a qualitative follow-on study to a randomized controlled trial (RCT) to understand the experiences of family physicians using survivorship care plans to support the follow-up of breast cancer patients. Methods: A subset of family physicians whose patients were enrolled in the parent RCT in Ontario and Nova Scotia were eligible for this study. In interviews, the physicians discussed survivorship care plans (intervention) or usual discharge letters (control), and their confidence in providing follow-up cancer care. Results: Of 123 eligible family physicians, 18 (10 intervention, 8 control) were interviewed. In general, physicians receiving a survivorship care plan found only the 1-page care record to be useful. Physicians who received only a discharge letter had variable views about the letter’s usefulness; several indicated that it lacked information about potential cancer- or treatment-related problems. Most physicians were comfortable providing care 3–5 years after diagnosis, but desired timely and informative communication with oncologists. Conclusions: Although family physicians did not find extensive survivorship care plans useful, discharge letters might not be sufficiently comprehensive for follow-up breast cancer care. Effective strategies for two-way communication between family physicians and oncologists are still lacking.