Aim of the review: Use of smart devices to provide real-time cardiopulmonary resuscitation (CPR) feedback in the context of out-of-hospital cardiac arrest (OHCA) has considerable potential for improving survival. However, the findings of previous studies evaluating the effectiveness of these devices have been conflicting. Therefore, we conducted a systematic review of the literature to assess the utility of smart devices for improving the quality of CPR during CPR training.Data sources: Thirteen electronic databases were searched. The articles were reviewed according to the eligibility criteria. CPR quality was evaluated based on the rates and depths of chest compression, and the proportion of adequate depth of chest compressions.Results: Ultimately, 11 studies (5 randomised controlled trials, 1 randomised trial, and 5 randomised cross-over trials) were selected for this systematic review. Eight of these studies used smartphones and three used smartwatches. This review did not find an apparent benefit from smart device use during CPR in terms of maintaining the recommended compression rates and depths of chest compressions. However, all three smartwatch studies reported that the proportion of chest compressions of adequate depth was significantly improved with smartwatch use (smartwatch group vs. nonsmartwatch group in the three studies: 65.01% vs. 45.15%, p = 0.01; 64.6% vs. 43.1%, p = 0.049; 98.7% vs. 79.3%, p = 0.002).Conclusion: This review does not find durable evidence for usefulness of smart devices in CPR training. However, the smartwatches may improve the accuracy of chest compression depth. Future studies with larger sample sizes might be necessary before reaching a firm conclusion.