The aim of this study was to describe radiotherapy patients’ perceptions of patient-centred cancer care by assessing the proportion and characteristics of patients identifying the need for better care. Cancer patients receiving radiotherapy at four metropolitan treatment centres in Australia completed a touchscreen computer survey assessing their perception of whether their wellbeing would have been improved by better care. Demographic, disease and psychological characteristics were assessed. We aimed to recruit 450 patients. Of 508 eligible radiotherapy patients, 344 (68%) completed the survey. The proportion of respondents identifying that their wellbeing would have been greatly improved by better care across the eight domains of patient centred care was: information and communication (22%, 95% CI: 18-27%); emotional and spiritual support (22%, 95% CI: 18-27%); management of physical symptoms (21%, 95% CI: 17-26%); support for friends and family (21%, 95% CI: 17-26%); practical concerns (20%, 95% CI: 16-25%); access to care (18%, 95% CI: 14-23%); relationship changes (16%, 95% CI: 13-21%), and staff approachability (12%, 95% CI: 8.9-16%). Thirty-one per cent of respondents (95% CI: 26-36%) endorsed two or more of these domains where better care would have greatly improved their wellbeing. Patients in younger age groups (p <0.0001) and migrants to Australia (p = 0.02) had higher odds of endorsing multiple domains. Results of this study have indicated several areas where treatment centre quality improvement efforts should be directed. However, it is also important to consider how to improve quality of care at the level of the individual. Further investigation of why the identified subgroups appear more likely to identify that better care would be of benefit to their wellbeing may assist in developing targeted interventions to improve patient-centred care and other outcomes for these groups.