Objective: This study aimed to define the ethnographic composition and assess the health-related quality of life (HRQoL) of a large population of undocumented patients with end-stage renal disease (ESRD) seeking emergent dialysis in the emergency department (ED) of a large public hospital in the United States. Design: All ESRD patients presenting to the hospital's main ED were identified during a 4-week consecutive enrollment period. Consenting patients completed two surveys-an ethnographic questionnaire and the validated kidney disease quality of life-36 (KDQOL-36) instrument. Setting: The study was conducted at a large county hospital in Dallas, Texas. In 2013, the hospital recorded >50,000 ED visits and administered approximately 6,000 dialysis treatments to ED patients. Participants: 88 of 101 unfunded patients presenting to the ED during the study period consented to participate, resulting in an 87.1% response rate. 65 of these patients were undocumented immigrants. Main Outcome Measures: Quantitative scores for the 5 subscales of the KDQOL-36 were calculated for the study population. Results: Measures of physical and mental health in our study population were lower than those published for scheduled dialysis patients. 79.5% of our patients lost employment due to their dialysis requirements. At least 71.4% of the study patients were unaware that they required dialysis before immigrating to the United States. Conclusions: Quality of life scores were found to be low among our population of undocumented emergent dialysis patients. Our data also provide some evidence that availability of dialysis at no cost is not a primary driver of illegal immigration of ESRD patients to the United States.