To investigate the effectiveness of brief bedside cardiopulmonary resuscitation (CPR) training to improve the skill retention of hospital-based pediatric providers. We hypothesized that a low-dose, high-frequency training program (booster training) would improve CPR skill retention. CPR recording/feedback defibrillators were used to evaluate CPR quality during simulated arrest. Basic life support-certified, hospital-based providers were randomly assigned to 1 of 4 study arms: (1) instructor-only training; (2) automated defibrillator feedback only; (3) instructor training combined with automated feedback; and (4) control (no structured training). Each session (time: 0, 1, 3, and 6 months after training) consisted of a pretraining evaluation (60 seconds), booster training (120 seconds), and a posttraining evaluation (60 seconds). Excellent CPR was defined as chest compression (CC) depth ≥ one-third anterior-posterior chest depth, rate ≥90 and ≤120 CC per minute, ≤20% of CCs with incomplete release (>2500 g), and no flow fraction ≤ 0.30. Eighty-nine providers were randomly assigned; 74 (83%) completed all sessions. Retention of CPR skills was 2.3 times (95% confidence interval CI: 1.1-4.5; P=.02) more likely after 2 trainings and 2.9 times (95% CI: 1.4-6.2; P=.005) more likely after 3 trainings. The automated defibrillator feedback only group had lower retention rates compared with the instructor-only training group (odds ratio: 0.41 95% CI: 0.17-0.97; P = .043). Brief bedside booster CPR training improves CPR skill retention. Our data reveal that instructor-led training improves retention compared with automated feedback training alone. Future studies should investigate whether bedside training improves CPR quality during actual pediatric arrests.