Objective: To determine the prevalence and severity of constipation among persons receiving hospice care in the United States, using longitudinal patient-reported outcomes. Methods: Data was obtained from excelleRx, Inc, a national hospice pharmacy. Patient-reported symptom outcome data were collected by telephone for each patient by trained research assistants within the first three days of hospice admission. Data collection continued every three to four days until patients were discharged, or unable or unwilling to report data or dead. Patients rated constipation on a four-point verbal rating scale of none, mild, moderate, and severe. The sample for our analysis came from five participating hospices and included all discharged or deceased patients receiving home hospice care with an admission assessment record and at least one subsequent telephone assessment for constipation between April 1, 2006 and October 20, 2007. The first patient reported constipation assessment score post hospice admission was used to estimate prevalence and severity of constipation. Results: A total of 309 patients met the inclusion criteria, the majority of which were female (n=167, 54%), Caucasian (n=282, 91%), >65 years of age (n=238, 77%) and had a primary diagnosis of cancer (n=223, 72%). All patients were prescribed opioid therapy during their hospice experience. Constipation was reported at the first assessment post admission by 26% of the patients (n=80), 28.7 % of patients with cancer (n=64) and 18.6% of patients without cancer (n=16). Most patients who reported constipation were female (58.8%) and >65 years (78.8%). Constipation intensity was rated as mild (n=32; 40%), moderate (n=23; 28.8%) and severe (n=25; 31%). Conclusion: Constipation was reported by approximately 25% of the hospice patients, a third of whom rated their constipation as severe. A substantial number of hospice patients may require aggressive management of constipation. This information may be useful as a process indicator of quality of care.