Lewy body dementia (LBD), including Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB), is a common and burdensome dementia. Determining risk factors and predictors can provide insights into pathogenesis and guide treatment efforts. In this systematic review, we searched PubMed, Embase, and Web of Science for longitudinal studies assessing risk/prodromal factors; including participants without dementia at baseline; with LBD as the outcome; with good/high quality based on the Newcastle-Ottawa Quality Assessment Scale. Across 167 included studies, more consistently reported factors were older age, male sex, APOEe4, GBA, changes in cognition, mood, behavior, sleep, gait/posture, speech, parkinsonism, smell loss, autonomic dysfunction, white matter disease on MRI, lower CSF amyloid β42 and higher CSF/blood neurofilament light chain. The majority focused on clinical factors preceding PDD with cohorts from North America and Europe, limiting generalizability. Further efforts with more representative cohorts are needed to better identify people at risk for LBD.