BackgroundAdvance care planning (ACP) can help to elicit cancer patients' preferences in a discussion process to promote person‐centred medical decision‐making. Expectations are known to be highly relevant determinants of decisional processes. So far, however, little is known about cancer patients' expectations of ACP that lead to acceptance or refusal of the programme. The presented study, therefore, aims to explore cancer patients' expectations of ACP.MethodsSemi‐structured interviews were conducted with a purposeful sample of 27 cancer patients consenting to or refusing a newly implemented ACP programme in a German university hospital. Data were analysed using typological content analysis.ResultsWe identified five different expectation clusters in relation to ACP. Consenting participants held expectations about the impact of ACP that were either ‘ego‐centred’ or ‘family‐centred’. Refusers had expectations based on ignorance and misinformation, or—if they had already completed an advance directive—expectations to avoid unpleasant redundancy, perceiving no additional benefit but a burden from ACP. Finally, refusers in particular expressed expectations of delegated responsibility at the end of life, including anticipation of proxy decision‐making.ConclusionOur study results suggest that expectation‐modifying measures could be taken to positively influence cancer patients' expectations and thus the acceptance of ACP. In this respect, reducing ignorance and misguided expectations plays a decisive role. Especially in family constellations with expected delegation of responsibility and dependence at the end of life, it might be important to promote ACP as a family‐intervention to improve family outcomes.