Clinical audits suggest that prognosis is often not discussed with cancer patients, and cancer patients often over- or underestimate their prognosis. Doctors wish to convey information honestly and sensitively, but are often unsure how best to achieve this. An evidence base and guidelines in this area are lacking. This study aimed to obtain patient and health professional views on optimal ways of presenting prognosis to patients with metastatic breast cancer. Qualitative methods were used to generate participant views and experiences. Seventeen patients and 13 health professionals working in cancer care participated in structured interviews, which were audio-taped and transcribed. Sampling was discontinued when informational redundancy was achieved. The transcribed interviews were content analysed by a trained assessor using the constant-comparative method. Seven primary themes were identified, including: communication within a caring, trusting, long-term relationship; open and repeated negotiations for patient preferences for information; clear, straightforward presentation of prognosis where desired; strategies to ensure patient understanding; encouragement of hope and a sense of control; consistency of communication within the multi-disciplinary team; communication with other members of the family. Communication about prognosis in a metastatic setting requires considerable resources from both patients and doctors. Nevertheless, a number of useful strategies were identified. A quantitative study obtaining feedback from a large and representative sample of patients with metastatic cancer is now in progress, to confirm patient preferences for the communication styles identified in this qualitative study.