This study generated the first-time evidence on national prevalence on Dementia among elderly population of urban and rural community in Bangladesh. The study also revealed the divisional prevalence and significant regional variation in the prevalence. Age, Sex, Gender, Level of education, occupation etc. seemed to be important precipitating factors for cognitive impairment in elderly population. The study also showed that multi morbidity among the dementia patients was substantial. This study generated evidence to make geriatric care available at the primary health care settings and will also help in policy implication for strengthening NCD and NCD management in root level.