Two methods were used in an attempt to determine whether written consent forms serve a useful medicolegal purpose in Australian radiotherapy departments. First a survey was posted to all practising radiation oncologists to ask about their use of written consent forms and whether they had ever been useful in any claims made against them. Second, the largest medical defence organization in Australia was contacted for de-identified details about every claim ever made against a radiation oncologist. The survey yielded a response rate of 50.3%. Only one respondent indicated that any consent form had ever played a role in any claim and was not prepared to discuss it. Many radiation oncologists did not routinely use a consent form and its use could not be considered standard practice. The submitted consent forms generally did not contain warnings to the patient about specific risks of treatment. The details of the previous claims provided by the medical defence organization indicated that more often claims arose from circumstances in which a written consent form could not provide any useful protection such as radiation dose calculation errors. The medicolegal value of written consent forms in radiotherapy seems low, although further research may be necessary before dispensing with them completely.