Background: Alcohol and illicit drug use is prevalent among women of childbearing age and may lead to higher risk for substance-exposed pregnancy and related health consequences for both women and their offspring. Technology-based interventions (TBIs) are increasingly used to prevent or reduce substance use among women of childbearing age. The efficacy of these approaches, however, is unclear. This review critically reviewed existing research evidence from randomized controlled trials (RCTs) on the efficacy of TBIs in preventing and reducing alcohol and illicit drug use among childbearing-aged women.Methods: Seven electronic databases were searched to identify eligible studies. Two reviewers independently screened studies, extracted data, and assessed risks of bias. Robust variance estimation in meta-regression was used to estimate effect sizes and conduct moderator analyses.Results: Fifteen RCTs including 3,488 participants were included in the systematic review. Metaanalysis results based on 13 RCTs suggest that TBIs were efficacious relative to control conditions in preventing and reducing substance use among women of childbearing age (d = 0.19, 95% CI = 0.02, 0.35). Preliminary moderator analysis results suggest that the efficacy of TBIs might not vary by participant age, race/ethnicity, the type of technology used, or whether a virtual health assistant was used. TBIs' efficacy in terms of specific substance use types (alcohol use and illicit drug use) or control types (inactive control and active controls) was inconclusive, due to the limited number of studies in each category.Conclusions: This systematic review and meta-analysis found evidence of TBIs' efficacy in reducing alcohol and illicit drug use among women of childbearing age. Implications for future research and practice are discussed.