Background: The purpose of this study was to systematically review the existing literature on grief in family carers of people with dementia in Japan and to synthesise the evidence on the prevalence and associated factors of pre- and post-death grief of the carers.

Methods: CiNii Research, J-STAGE, and ICHUSHI were searched for studies published in Japanese and MEDLINE, PsycINFO, and CINAHL for studies written in English up to 30 November, 2023.

Results: Of the 315 references identified, eight studies that met the eligibility criteria were included: six studies investigated pre-death grief, and two studies investigated post-death grief. One low-quality study reported the prevalence of pre-death grief (28.6%), and no studies reported the prevalence of complicated grief as post-death grief. Less social support and greater levels of depressive symptoms and caregiving burden were associated with greater levels of pre-death grief, while no studies reported significant factors associated with complicated grief. Most of the studies had small sample sizes and poor study quality.

Conclusions: Limited evidence makes it difficult to draw conclusions about the prevalence of pre-/post-death grief and associated factors among family carers of people with dementia in Japan. Future studies focusing on grief using validated measures are needed.