Studies estimate prolonged stays in acute and sub-acute facilities for patients with dementia. Actuarial projections suggest prolonged stays in long term care facilities for patients with dementia. To test these predictions, we assessed whether patients with dementia stay in skilled nursing facilities (SNF) longer than patients without dementia. We obtained medical records of 5,373 residents discharged from a SNF between 1996 and 2001. Residents were identified as having dementia by ICD-9 codes. Age, sex and length of stay (LOS), measured in days from admission to discharge or death, were gathered. Mean LOS for patients with dementia (92.7 +/- 313.0, n = 758) was significantly longer than non-demented patients (29.7 +/- 136.8, n = 4615, p < 0.001). In a subset of individuals who stayed until death, the mean LOS for patients with dementia (202.9 +/- 528.6, n = 195) also was significantly longer than for non-demented patients (91.8 +/- 300.5, n = 610, p < 0.001). LOS was increased for demented patients even within age groups. Thus, patients with dementia stay in SNFs significantly longer from entry until discharge or death. It is likely that demented patients enter for non-physical, cognitive related reasons. These results may help families and institutions plan for long-term care.