Background <p>The aim of the study was to ascertain the efficacy of interferential current-transcutaneous electrical sensory stimulation (IFC-TESS) in treating patients with severe dementia accompanied by dysphagia who reside in long-term care facilities.</p> Methods <p>We conducted a comparative intervention study. Forty-four patients with severe dementia and dysphagia in a long-term care facility were administered IFC-TESS for 15 min twice daily, 5 days a week. The clinical findings before and after 3 weeks of intervention were compared.</p> Results <p>The study participants showed significant improvement in oral calorie intake after the intervention (<i>p&lt;</i>0.05). The oral calorie intake indicated an improved nutritional state.</p> Conclusions <p>IFC-TESS may be effective in improving oral intake by patients with dementia.</p> Trial registration <p>The trial was registered at UMIN-CTR under the identifier UMIN000032262 (Registration date: 16/04/2018).</p>