Background. Advance care planning (ACP) has been gaining prominence for its perceived benefits for patients in enhancing patient autonomy and ensuring high-quality end-of-life-care. Moreover, it has been postulated that ACP has positive effects on families and health professionals and their relationship with the patient. However, there is a paucity of studies examining the views of GPs on this issue. Objective. To explore GP views on the impact that ACP has on interpersonal relationships among those involved in the patient's care. Method. Semi-structured, open-ended interviews of a purposive sample of 17 GPs. Interview transcripts were analysed using constructionist grounded theory methodology with QSR NVivo 9 software. Results. ACP was seen as having both positive and negative impacts on interpersonal relationships. It was thought to enhance family relationships, help resolve conflicts between families and health professionals and improve trust and understanding between patients and health professionals. Negatively, it could take the family's attention away from patient care. The link between ACP and interpersonal relationships was perceived to be bidirectional-the nature of interpersonal relationship that patients have with their families and health professionals has a profound impact on what form of ACP is likely to be useful. Conclusion. Our study highlights the importance that GPs place on the link between ACP and the patient's interpersonal context. This has implications on how ACP is conducted in primary care settings that are considerably different from other care settings in their emphasis on continuity of care and long-term nature of relationships. © The Author 2012. Published by Oxford University Press. All rights reserved.