Objectives: The present study aimed to explore the modifiable factors of behavioural and psychological symptoms of dementia (BPSD) among patients residing at home in terms of patient, caregiver and environmental factors. Methods: A cross-sectional survey of 193 patients with dementia residing at home and their caregivers who visited the memory clinic of the Department of Neurology in a tertiary (the highest level) hospital in China from November 2018 to May 2019 was performed. Results: Exacerbated BPSD were associated with patient (old age, high education level, increased dementia severity, and the use of psychotropic drugs), caregiver (low positive aspects and high expressed emotion) and environmental (poor home environment) factors. The use of psychotropic drugs by the patient, positive aspects and expressed emotions of the caregiver, and home environment were modifiable factors that provided evidence for the direction of intervention for BPSD among patients residing at home.