Efforts to improve end-of-life care have focused primarily on patients with cancer. High-quality end-of-life care is also critical for patients with other illnesses. To compare patterns of end-of-life care and family-rated quality of care for patients dying with different serious illnesses. A retrospective cross-sectional study was conducted in all 146 inpatient facilities within the Veteran Affairs health system among patients who died in inpatient facilities between October 1, 2009, and September 30, 2012, with clinical diagnoses categorized as end-stage renal disease (ESRD), cancer, cardiopulmonary failure (congestive heart failure or chronic obstructive pulmonary disease), dementia, frailty, or other conditions. Data analysis was conducted from April 1, 2014, to February 10, 2016. Palliative care consultations, do-not-resuscitate orders, death in inpatient hospices, death in the intensive care unit, and family-reported quality of end-of-life care. Among 57 753 decedents, approximately half of the patients with ESRD, cardiopulmonary failure, or frailty received palliative care consultations (adjusted proportions, 50.4%, 46.7%, and 43.7%, respectively) vs 73.5% of patients with cancer and 61.4% of patients with dementia (P < .001). Approximately one-third of patients with ESRD, cardiopulmonary failure, or frailty (adjusted proportions, 32.3%, 34.1%, and 35.2%, respectively) died in the intensive care unit, more than double the rates among patients with cancer and those with dementia (13.4% and 8.9%, respectively) (P < .001). Rates of excellent quality of end-of-life care reported by 34 005 decedents' families were similar for patients with cancer and those with dementia (adjusted proportions, 59.2% and 59.3%; P = .61), but lower for patients with ESRD, cardiopulmonary failure, or frailty (54.8%, 54.8%, and 53.7%, respectively; all P ≤ .02 vs patients with cancer). This quality advantage was mediated by palliative care consultation, setting of death, and a code status of do-not-resuscitate; adjustment for these variables rendered the association between diagnosis and overall end-of-life care quality nonsignificant. Family-reported quality of end-of-life care was significantly better for patients with cancer and those with dementia than for patients with ESRD, cardiopulmonary failure, or frailty, largely owing to higher rates of palliative care consultation and do-not-resuscitate orders and fewer deaths in the intensive care unit among patients with cancer and those with dementia. Increasing access to palliative care and goals of care discussions that address code status and preferred setting of death, particularly for patients with end-organ failure and frailty, may improve the overall quality of end-of-life care for Americans dying of these illnesses.