Objectives: This study examined the knowledge, attitudes and practices of clinicians in promoting physical activity to prostate cancer survivors. Design: A purposeful sample was used and cross-sectional data were collected using an anonymous, self-reported online questionnaire or an identical paper-based questionnaire. Settings: Health services and online questionnaire. Methods: Clinicians were invited to complete the questionnaire which measured their knowledge, attitudes and practices relating to physical activity for their patients. Results: Thirty-one clinicians completed a questionnaire. Most participants were men (71%), aged 30-40 years (45.2%), and radiation oncologists (35.5%). Although clinicians recognized the benefits of physical activity for their patients, few always gave advice about physical activity. Advice was verbal in nature, very few provided written material and none referred patients to an exercise specialist. Older age, a belief that physical activity reduces side effects of treatment, higher confidence and disagreement that physical activity has risks were associated with higher frequency of providing physical activity advice. Over half of the clinicians (55%) reported that advising patients on physical activity was not part of their role. Conclusions: This study provides preliminary evidence that physical activity advice may not be provided routinely to prostate cancer survivors. It is important for future research to address the involvement of clinicians in physical activity promotion so that holistic care is provided.