Abstract Objective Futile treatment, which by definition cannot benefit a patient, is undesirable. This research investigated why doctors believe that treatment that they consider to be futile is sometimes provided at the end of a patient\u27s life. Design Semistructured in-depth interviews. Setting Three large tertiary public hospitals in Brisbane, Australia. Participants 96 doctors from emergency, intensive care, palliative care, oncology, renal medicine, internal medicine, respiratory medicine, surgery, cardiology, geriatric medicine and medical administration departments. Participants were recruited using purposive maximum variation sampling. Results Doctors attributed the provision of futile treatment to a wide range of inter-related factors. One was the characteristics of treating doctors, including their orientation towards curative treatment, discomfort or inexperience with death and dying, concerns about legal risk and poor communication skills. Second, the attributes of the patient and family, including their requests or demands for further treatment, prognostic uncertainty and lack of information about patient wishes. Third, there were hospital factors including a high degree of specialisation, the availability of routine tests and interventions, and organisational barriers to diverting a patient from a curative to a palliative pathway. Doctors nominated family or patient request and doctors being locked into a curative role as the main reasons for futile care. Conclusions Doctors believe that a range of factors contribute to the provision of futile treatment. A combination of strategies is necessary to reduce futile treatment, including better training for doctors who treat patients at the end of life, educating the community about the limits of medicine and the need to plan for death and dying, and structural reform at the hospital level.