This paper explores reasons why cancer and transplant patients are at greater risk for food-borne illnesses and which pathogens and food-handling behaviors are of particular concern. Cancer and bone marrow transplant patients experience neutropenia because of medical treatments, whereas patients with solid organ transplants become immunosuppressed from a pharmacological regimen to prevent rejection of the transplanted organ. Opportunistic infections, including food-borne illnesses, may occur during periods of immunosuppression. Food-handling behaviors and practices to control food-borne illnesses were presented to focus groups and during interviews with cancer and transplant patients and health care providers. Credibility of the food safety information, credibility of the person providing the advice, and sensitivity to the restrictions imposed on the patient's lifestyle by food safety guidance were key themes from the focus group and interview study. The information gathered will help health care providers aid the cancer or transplant patient with their knowledge and understanding of food safety and their greater risk for food-borne infections.