Better understanding of the quality of life among nursing home residents with dementia is important for developing interventions. The objectives of this cross-sectional study were to examine factors associated with poor health-related quality of life in older people with dementia living in nursing homes in Hanoi, Vietnam. In-person interviews were conducted with 140 adults who were 60 years and older with dementia, and information about their quality of life was obtained using the Quality of Life in Alzheimer's Disease (QOL-AD) scale. The sociodemographic and clinical factors associated with poor health-related quality of life (lowest quartile) were assessed through the results of physical tests, interviews with nursing home staff, and review of medical records. The average age of the study sample was 78.3 years, 65% were women, and their average QOL-AD total score was 27.3 (SD = 4.4). Malnutrition, total dependence in activities of daily living, and urinary incontinence were associated with poor quality of life after controlling for multiple potentially confounding factors. Our findings show that Vietnamese nursing home residents with dementia have a moderate total quality of life score, and interventions based on comprehensive geriatric assessment remain needed to modify risk factors related to poor health-related quality of life.