Background: Advance care planning (ACP) involves documentation of patients’ preferred place of death (PoD). This assumes that patients’ preferred PoD will not change over time; yet, evidence for this is inconclusive. We aimed to assess the extent and correlates of change in patients’ preferred PoD over time. Materials and Methods: Using data from a cohort study of patients with advanced cancer in Singapore, we analyzed preferred PoD (home vs institution including hospital, hospice, and nursing home vs unclear) among 466 patients every 6 months for a period of 2 years. At each time point, we assessed the proportion of patients who changed their preferred PoD from the previous time point. Using a multinomial logistic regression model, we assessed patient factors (demographics, understanding of disease stage, ACP, recent hospitalization, quality of life, symptom burden, psychologic distress, financial difficulty, prognosis) associated with change in their preferred PoD. Results: More than 25% of patients changed their preferred PoD every 6 months, with no clear trend in change toward home or institution. Patients psychologically distressed at the time of the survey had increased likelihood of changing their preferred PoD to home (relative risk ratio [RRR], 1.02; 95% CI, 1.00–1.05) and to an institution (RRR, 1.06; 95% CI, 1.02–1.10) relative to no change in preference. Patients hospitalized in the past 6 months were more likely to change their preferred PoD to home (RRR, 1.56; 95% CI, 1.07–2.29) and less likely to change to an institution (RRR, 0.50; 95% CI, 0.28–0.88) relative to no change in preference. Conclusions: The present study provides evidence of instability in the preferred PoD of patients with advanced cancer. ACP documents need to be updated regularly to ensure they accurately reflect patients’ current preference.