Background Although childhood adversities are known to predict increased risk of post-traumatic stress disorder (PTSD) after traumatic experiences, it is unclear whether this association varies by childhood adversity or traumatic experience types or by age. Aims To examine variation in associations of childhood adversities with PTSD according to childhood adversity types, traumatic experience types and life-course stage. Method Epidemiological data were analysed from the World Mental Health Surveys (n = 270l7). Results Four childhood adversities (physical and sexual abuse, neglect, parent psychopathology) were associated with similarly increased odds of PTSD following traumatic experiences (odds ratio (OR) = 1.8), whereas the other eight childhood adversities assessed did not predict PTSD. Childhood adversity-PTSD associations did not vary across traumatic experience types, but were stronger in childhood-adolescence and early-middle adulthood than later adulthood. Conclusions Childhood adversities are differentially associated with PTSD, with the strongest associations in childhood-adolescence and early-middle adulthood. Consistency of associations across traumatic experience types suggests that childhood adversities are associated with generalised vulnerability to PTSD following traumatic experiences. Declaration of interest in the past 3 years, R.C.K. received support for his epidemiological studies from Sanofi Aventis; was a consultant for Johnson & Johnson Wellness and Prevention, Shire, Takeda; and served on an advisory board for the Johnson & Johnson Services inc Lake Nona Life Project. R.C.K. is a co-owner of DataStat inc, a market research firm that carries out healthcare research. In the past 3 years, K.D. has received personal fees from Lundbeck, Servier and Johnson & Johnson. In the past 3 years, DJ.S. has received research grants and/or consultancy honoraria from AMBRF/The Foundation for Alcohol Research, Biocodex, Cipla, Lundbeck, National Responsible Gambling Foundation, Novartis, Servier and Sun. in the past 3 years, N.K. has received support (in the form of consultancy fees, lecture fees and royalties) from Aishin-Seiki, EAP Consulting, igaku-Shoin, Japan Dental Association, Japan Housing Finance Agency, Japan Productivity Center, Junpukai Health Care Center, Meiji, Nanko-do, Nanzan-do, Occupational Health Foundation, Osaka Chamber of Commerce and industry, otsuka and Sekisui Chemicals, PHP Publication and Taishu-kan. He has received research grants from infocom Ltd, Japan Management Association, Japanese Ministry of Education, Science, and Technology, Japanese Ministry of Health, Labor and Welfare and SoftBank Corp. Fujitsu Software Technologies Ltd has provided support to N.K. in the form of grants and royalties.