Delirium is a troubling complication in hospitalized older patients with cancer. Although preventable and potentially reversible, delirium may be prolonged. Persistent delirium at the time of hospital discharge is common and associated with multiple adverse outcomes. We conducted a secondary data analysis to examine delirium resolution in 43 hospitalized older patients with cancer who had prevalent or incident delirium. We describe trajectories of delirium resolution and evaluate differences in patients with and without delirium resolution. Delirium was assessed using the NEECHAM confusion scale. Forty-one of the 43 patients had delirium during hospitalization before discharge; 2 had delirium only at the time of discharge. Although delirium resolved in 13 patients, a significant majority (70%) had delirium at discharge. Patients with delirium resolution were less functionally impaired before hospitalization and exhibited fewer etiologic risk patterns at admission. Mild delirium was more likely to resolve than severe delirium. All patients with chronic cognitive impairment had persistent delirium. Care for hospitalized older patients with cancer should incorporate delirium prevention and intervention strategies. Caregiver education, communication between providers, and follow-up are critical when delirium persists. Additional research focusing on the management and impact of persistent delirium in hospitalized older patients with cancer is needed.