Objectives: To evaluate the relationship between Willis-Ekbom Disease/Restless Legs Syndrome and iron deficiency anemia in older people with dementia.

Methods: A cross-sectional study was conducted with 70 older people diagnosed with dementia and restless leg syndrome in a Psychogeriatric outpatient clinic in a city in the interior of São Paulo, Brazil. The older people filled in instruments of sociodemographic characterization, measures to evaluate the Restless Legs Syndrome, neuropsychiatric symptoms, sleep quality, sleepiness and cognition. Blood data were also collected levels of creatinine, ferritin, red blood cells, hemoglobin and hematocrit, the latter collected in the patients’ medical records.

Results: The sample consists mostly of older people with mixed dementia (i.e., Alzheimer’s disease + Vascular Dementia), with 39% of female patients and mean age of 77.80 years (9.36). This study identified a frequency of 15.7% of Restless Legs Syndrome. Patients with the syndrome present more frequency of neuropsychiatric symptoms, worse sleep quality, higher index of body mass and lower levels of ferritin (p < .05).

Conclusions: A frequency of 15.7% was identified for restless leg syndrome among patients with dementia. In addition, patients with the syndrome have ferritin deficiency.