Background: Delirium in advanced cancer inpatient ranges between 13% and 85%. Reasons for this variability on the reported data could be related to the setting where they are admitted. Methods: This is an observational, comparative, prospective study on delirium diagnosis and delirium course of advanced cancer inpatients in two different palliative care settings. Hospice (C1) versus palliative care supportive team (C2). Differences between delirium precipitants, delirium treatment, and delirium survival were observed. Results: From 582 consecutive admissions, 494 from C1 and 88 from C2, finally 227 patients met inclusion criteria, were entered in the study. Total population delirium rate at admission, if we add both centers, was 57 patients (25%), 46 (26%) from C1 and 11 (22%) from C2; no statistically significant differences between delirium rate at admission between the two centers were found (chi(2)). When delirium course between delirious patients admitted in C1 and C2 was analyzed, a significantly higher rate of delirium reversibility was found in C2 [11/14 (78%)] versus [9/65 (14%)] in C1 (chi(2) p <= 0.001). Conclusion: The frequency of delirium at admission and during the hospitalization in advanced cancer patients does not seem to be related to the setting, what seems to be related is the delirium course.