This study describes the health problems and comorbid illnesses of nursing home (NH) residents with advanced dementia (n=123) and identifies correlates of staff-identified pain. Study participants were residents of 3 NHs in Maryland, their surrogate decision makers and their physicians. Residents' cognitive function was assessed at study enrollment, and their medical records were reviewed to identify all health problems/illnesses and use of pain medications during the 6 months before their enrollment. The most prevalent health problems were skin problems (95%), nutrition/hydration problems (85%), psychiatric/behavioral problems (85%), gastrointestinal problems (81%), and infections (80%). Sixty-three percent of residents had recognized pain, and 95% of those residents received pain medications. In a multivariate regression analysis, staff-identified pain was associated with aspiration (P=0.008), peripheral vascular disease (P=0.021), musculoskeletal disorders (P=0.032), higher cognitive function (P=0.013), and use of pain medications, including nonopiates (P=0.004) and the combination of opiates and nonopiates (P=0.001). NH residents with advanced dementia experience a complex mixture of multiple chronic and acute comorbidities. These results suggest the need for clinicians in long-term care facilities to be vigilant in assessing and treating pain, particularly as cognitive function declines in those with advanced dementia.