Although positive effects of physical activity in cancer survivors are well-established, survivors are often not active enough to benefit. Exercise Referral Schemes are under-used by cancer survivors, largely due to lack of referral. A physical activity promotion pack, “MoveMore”, was developed by Macmillan in 2011, followed by a campaign to promote it to all cancer survivors in Wales. However education alone is not sufficient to effect behaviour change. The aim of this project was to develop a behaviour change intervention to reinforce the “MoveMore” message, and promote physical activity for cancer survivors. Following the Medical Research Council framework, a systematic review was conducted to determine the effectiveness of physical activity education materials, a literature review identified relevant theory to underpin the proposed intervention, focus groups explored cancer survivors’ views about physical activity advice and informed the refinement of the intervention. Finally a survey of health professionals explored knowledge and beliefs about promoting physical activity to cancer survivors. The systematic review findings indicated that education materials may increase physical activity levels in cancer survivors. Furthermore reinforcement based on behaviour change theories complements readiness to initiate or increase exercise. Focus group participants wanted consistent, tailored and face-to-face physical activity advice as part of their standard care. The survey confirmed the focus group findings but highlighted inconsistency, with health professionals lacking knowledge or confidence to give physical activity advice. Physical inactivity in cancer survivors needs addressing to improve quality of life. Behaviour change interventions need to be theory-driven and low-maintenance. The proposed 12 weekly text message reinforcement intervention to promote physical activity in cancer survivors may be beneficial if integrated into existing health services. The feasibility of the proposed intervention can be tested in a pilot randomised controlled trial, the protocol of which has been drafted as part of this research work.