This meta-analysis aimed to estimate the prevalence of cerebral amyloid pathology in individuals without dementia, using data from 55 studies. The analysis included 7,583 participants aged 18 to 100 years, categorized into normal cognition, subjective cognitive impairment (SCI), and mild cognitive impairment (MCI). The prevalence of amyloid pathology increased from 10% at age 50 to 44% at age 90 among those with normal cognition, from 12% to 43% among those with SCI, and from 27% to 71% among those with MCI. Amyloid positivity was more common in individuals with the APOE ε4 genotype and highly educated individuals but not in those with different sex or biomarker modality. The study suggests a 20- to 30-year interval between the onset of amyloid positivity and dementia, highlighting the potential for preventive treatments.This meta-analysis aimed to estimate the prevalence of cerebral amyloid pathology in individuals without dementia, using data from 55 studies. The analysis included 7,583 participants aged 18 to 100 years, categorized into normal cognition, subjective cognitive impairment (SCI), and mild cognitive impairment (MCI). The prevalence of amyloid pathology increased from 10% at age 50 to 44% at age 90 among those with normal cognition, from 12% to 43% among those with SCI, and from 27% to 71% among those with MCI. Amyloid positivity was more common in individuals with the APOE ε4 genotype and highly educated individuals but not in those with different sex or biomarker modality. The study suggests a 20- to 30-year interval between the onset of amyloid positivity and dementia, highlighting the potential for preventive treatments.