ABSTRACT Aim To conduct a comprehensive analysis of the conflicting evidence on substance use and misuse following mass traumas such as terrorist incidents. Methods We reviewed and synthesized evidence from 31 population-based studies using Bayesian meta-analysis and meta-regression. Results The majority of the studied were conducted in the aftermath of the terrorist attacks of 11 September 2001. Controlling for exposure, type of incident and time since the event occurred, 7.3% [95% credible interval (CrI) 1.1–32.5%] of a population can be expected to report increased alcohol consumption in the first 2 years following a terrorist event. There is, however, a 20% probability that the prevalence will be as high as 14%. The unadjusted prevalence of increased cigarette smoking following a terrorist event is 6.8% (95% Cr I 2.6–16.5%). Unadjusted reports of mixed drug use (including narcotics and prescription medications) was 16.3% (95% Cr I 1.3–72.5%). Conclusions These results underscore the potentially pervasive behavioral health effects of mass terrorism, and suggest that public health interventions may usefully consider substance use as an area of focus after such events.