Delirium in patients with COVID-19 can cause multiple adverse functional outcomes. However, the adverse cognitive effect in the elderly with dementia after surviving COVID-19 has not been widely described. We report a Case of a severe COVID-19 infection resulting in persistent cognitive decline. An 81-year-old male LTC resident with dementia, congestive heart failure, ischemic cardiomyopathy, diabetes, hypertension, depression, chronic urinary retention, depression, and anxiety who at baseline was wheelchair ambulatory, able to self-feed, and able to follow simple commands contracted the COVID-19 infection in July 2020.The patient was discharged to sub acute rehabilitation on day 45 of admission. Presently he is over 100 days out from contracting COVID-19 infection and despite slow improvements remains both cognitively and functionally below his prior baseline. Delirium is an indicator of severe illness in older adults. Moreover, delirium can present as the sole onset manifestation of COVID-19 infection in older patients with dementia. Delirium occurring at the onset of infection is predictive of high short-term mortality and significantly worse physical function. Moreover, cognitive impairment can persist and affect 70%-100% of patients at discharge. We present our Case with baseline dementia who developed a significant worsening of baseline cognition after a turbulent 45-day hospitalization for COVID-19 infection