Background: Inequities in the provision of palliative care for people with cardiac disease have been well documented in the literature. Despite experiencing significant palliative care needs, those with cardiac disease are less likely to be referred to specialist palliative care services and more likely to die in a hospital when compared to those with cancer. The unpredictable trajectory of heart failure has been identified as a key barrier to providing palliative care with many people experiencing a long period of stability with appropriate medical treatment. However, as the disease progresses and cardiac function deteriorates, exacerbations of acute decompensation can lead to what is often perceived to be 'sudden' death. The aim of this study is to explore the impact of uncertainty on how death is remembered by bereaved family members of people with heart disease. Methods: Thematic analysis of free text collected during a postal survey of bereaved family's experiences of healthcare services in the last 3 months of life using the New Zealand version of the VOICES questionnaire was undertaken. Data was analysed using a three-dimensional conceptual framework of "scientific uncertainty". Results: Eight hundred and twenty-seven completed questionnaires were received of which 12.6% (n = 105) indicated that they had cared for someone at the end of life with cardiac disease. Experiences of uncertainty were found to have a significant impact upon bereaved family. Four key themes were identified; distrust in healthcare professionals, stories left incomplete, loss, regret and missed opportunity and disempowerment. Conclusions: This study highlights the ongoing impact on bereaved family when uncertainty is not made explicit in conversations regarding end of life for people with heart disease. Timely and sensitive conversations regarding the uncertainty of when death may occur is an important factor in ensuring that bereaved family are not left with unresolved narratives. Reframing how we think and talk about uncertainty in end of life care is important, as clinicians' uncertainties may not always reflect or match up with families' uncertainties. Being explicit about our inability to be certain about the timing of death may thus lead to a more positive and complete experience for bereaved family.