This prospective, longitudinal study explored changes in and modifiable factors associated with high self‐perceived burden to others (SPB) among a convenience sample of 276 dyads of terminally ill Taiwanese cancer patients and their family caregivers over patients’ last year of life. High SPB was evaluated by scores ≥20 on the Self‐Perceived Burden Scale. Modifiable factors of high SPB included factors related to both patients (i.e., symptom distress, functional dependence and coping capacity) and caregivers (i.e., caregiving burden, depressive symptoms and quality of life [QOL]). Modifiable factors of high SPB were identified by multivariate logistic regression modelling with the generalised estimating equation while controlling for demographic factors. We found that patients tended to experience high SPB if they had more symptom distress. In contrast, the likelihood of high SPB was significantly lower if patients had greater coping capacity and their caregivers reported better QOL. High SPB was not associated with patients’ functional dependence, caregivers’ caregiving burden and depressive‐symptom level while providing end‐of‐life (EOL) care, and time proximity to death. Healthcare professionals may alleviate terminally ill cancer patients’ high SPB at EOL through palliative care that adequately manages patients’ physical symptom distress, enhances patients’ coping capacity and improves family caregivers’ QOL.