• Parents of children and adolescents occasionally request nondisclosure of a diagnosis to the patient. This ethical dilemma was analyzed using a case in which parents of a child with cystic fibrosis demanded that the physician not reveal the diagnosis to their daughter. The case study helps to identify the specific clinical factors that may be considered when confronting similar dilemmas in other cases. Any justification for lying to the patient or hiding information must derive from clinical circumstances that override the basic moral duty to tell the truth. The physician, the disease, the patient, and the family are all pertinent to the ethical decision of disclosure. These factors may change over time with the natural history of the disease and the maturation of the patient.