Aims This study aimed to describe symptom prevalence of pain, shortness of breath, anxiety, and nausea and to identify factors associated with symptom relief in patients with heart failure during their last week of life.Methods and results This nationwide study used data from the Swedish Register of Palliative Care and the Swedish Causes of Death Certificate Register. The sample included 4215 patients with heart failure as the underlying cause of death. Descriptive statistics and logistic regression were used to analyse data. Pain was the most prevalent symptom (64.0%), followed by anxiety (45.1%), shortness of breath (28.8%), and nausea (11.4%). Pain was the most often totally relieved (77.5%), followed by anxiety (68.4%), nausea (54.7%), and shortness of breath (37.1%). Key aspects of palliative care such as documented palliative care in the patient record, individual medication prescriptions by injection, symptom assessment with validated scales, documented end-of-life discussions with patients and/or family members, and external consultation were significantly associated with symptom relief. Relief of pain, shortness of breath, anxiety, and nausea were significantly better managed in nursing homes and hospice/inpatient palliative care compared with care in hospitals. Conclusions The results show that key aspects of palliative care during the last week of life are significantly associated with symptom relief. Increased access to palliative care could provide a way to improve care during the last week of life for patients with heart failure. Home-based settings provided more symptom relief than hospitals, which may indicate that the latter focuses on treatments and saving lives rather than promoting life before death.