BACKGROUND: Agitated delirium is often observed in terminal patients with cancer. To clarify the risk factors for agitated delirium in terminal patients with cancer, we conducted a retrospective chart review of 126 patients with cancer who died at a university hospital in 2008. METHOD: As a working definition, we define agitated delirium as a score of 2 or more in item 9 of the Memorial Delirium Assessment Scale with diurnal variation. RESULTS: The results were as follows: agitated delirium was observed in 49 (42%) of the 115 patients, and it occurred within the last week before death in 49% of the patients. Univariate analysis revealed older age, male gender, smoking history, lung cancer, diabetes, and high C-reactive protein (CRP) value as major risk factors, while dendritic analysis revealed lung cancer, high CRP value, diabetes, older age, and smoking history as key factors for predicting agitation. CONCLUSION: It is necessary to consider risk factors in order to categorize terminal patients with cancer into high- and low-risk groups and undertake possible counter-measures.