Increasing numbers of patients with different types of dementia have resulted in the increasing medical care loads. It is not known whether explanatory factors for recurrent or prolong hospitalization were driven by the subtypes of dementia. We analyzed 203 dementia patients aged >65-year-old with a clinical diagnosis of Alzheimer disease (AD), vascular dementia (VaD), or Parkinsonism-related dementia (PRD). With a 4-year follow-up period, logistic regression analyses were used to identify predictors of dementia diagnosis, cerebrovascular risk factors, chronic systemic diseases, and the etiology for admission for recurrent (>4 times/4 years) or prolonged hospitalization stay (>14 days per hospitalization). There were 48 AD, 96 VaD, and 59 PRD patients that completed the 4-year study. The average length of hospital stay was significant, the shortest in AD and the longest in PRD (P = 0.01), whereas the frequency of hospitalization was not different among 3 dementia subtypes. Although delirium is the most common etiology for admission in the patients, diabetes mellitus (Odds ratio, OR = 2.79, P = 0.02), pneumonia (OR = 11.21, P < 0.001), and fall-related hip fracture (OR = 4.762, P = 0.029) were significantly associated with prolong hospitalization. Patients with coronary artery disease (OR = 9.87, P = 0.02), pneumonia (OR = 84.48, P < 0.001), urinary tract infection (OR = 55.09, P < 0.001), and fall-related fracture (OR = 141.7, P < 0.001) predict recurrent hospitalization. Dementia subtypes did not influence directly on the hospitalization courses. The etiologies for admission carried higher clinical significance, compared with the coexisted systemic diseases.