Background The subtypes and risk factors of neuropsychiatric symptoms remain largely unexplored in South‐East Asian populations. Objective We investigated the prevalence, subtypes, and risk factors, namely, demographic, medical morbidity, and cognitive impairment associated with neuropsychiatric symptoms in a South‐East Asian cohort of patients with mild cognitive impairment (MCI) and dementia. Methods A clinical cohort of 38 MCI and 198 mild–moderate dementia patients were assessed using the Neuropsychiatric Inventory‐Questionnaire. Results Neuropsychiatric symptoms were equally prevalent among patients with MCI (74%) and mild–moderate dementia (85%). Three subtypes of symptoms were identified for each diagnostic group; for MCI, they included mood disturbances, anxiety/sleep problems, and psychosis, while for dementia, the subtypes included behavioral disturbances, psychosis/mood, and hyperactive behaviors. The largest risk for neuropsychiatric symptoms for both MCI and dementia patients was male gender. Among patients with MCI, burden of cerebrovascular disease and global cognitive impairment were small risks for neuropsychiatric symptoms, while for patients with dementia, an older age (>65 years) was a small risk and lower educational attainment was a moderate risk. Discussion These findings contribute to the worldwide epidemiology of neuropsychiatric symptoms in MCI and dementia and highlight that the profile of symptoms, subtypes, and risks is fairly homogenous across Western and Asian cultures. Copyright © 2017 John Wiley & Sons, Ltd.