Background: Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) often face complex and evolving needs throughout recovery. Person-centred nursing (PCN) is essential in this context yet remains underexplored in specialised care settings. In Sweden, the Assessment of Rehabilitation Needs Checklist (ARNC) is commonly used in cancer care, but its role in supporting person-centred conversations has not been investigated. Aim: The aim of this study was to investigate how the use of the ARNC as a conversation tool promotes PCN within the allo-HCT context. Methods: This qualitative study was conducted at two major allo-HCT centres in Sweden. Data were collected through semi-structured interviews with patients (n = 16), focus group discussions with registered nurses (RNs, n = 16), and from 30 memos written by RNs. Reflexive thematic analysis was used. Results: Three overarching themes were developed: (1) Letting the Story Emerge, (2) Unmet Needs and (3) Structural Gaps in Practice. The ARNC facilitated individualised conversations and helped identify unmet needs, including sensitive or previously unvoiced concerns. However, lack of follow-up and organisational constraints, such as time pressure and fragmented care settings, limited its capacity to support shared care planning and sustained engagement. Conclusion: When used in dialogue, the ARNC has the potential to support person-centred nursing in allo-HCT by enabling narrative-based, needs-driven conversations. However, its effectiveness depends on structured follow-up and organisational conditions that promote relational care.