Introduction: Complementary therapy (CT) use amongst cancer patients is common and increasing. Further understanding of why cancer patients choose to have CTs and their expected benefits is needed. Methods: The aim was to compare cancer patients' expectations/attitudes regarding CTs pre- and post-CT. Multiple case study method (after Yin) was employed; this paper reports data from self-completed questionnaires completed before and after receipt of CTs by 113 patients from three cancer centres in North-West England (one hospice; one specialist cancer hospital and one community-based cancer support centre, all providing a range of CTs). Results: Expectations regarding potential benefits of CTs primarily related to psychosocial issues (91 comments). Fewer patients sought CTs for physical symptom relief (30 comments). Attitudes to CTs were positive both before and after therapy. CTs typically met or exceeded patients' expectations (99/113, 88%). There was no indication that patients were turning to CTs due to disillusionment with conventional treatment. Most viewed CTs as 'something extra' (pre-CT 77/108, 68%; post-CT 86/113, 76%), rather than 'integral' to treatment (pre-CT 11/108, 10%; post-CT 19/113, 17%). Conclusion: Patients had clear expectations of CTs, which were primarily related to psycho-social issues, both pre- and post-CT. Most patients were satisfied with CTs and perceived them as beneficial. However, few viewed CTs as integral to their cancer care. The data highlight a tension between needs or demand-led and evidence-based care provision. The exact role and unique contribution of CTs within cancer supportive care services needs further research.