Background: This systematic review evaluated the effectiveness of psychological interventions for reducing vaccination pain and related outcomes in children and adolescents. Design/Methods: Database searches identified relevant randomized and quasi-randomized controlled trials. Data were extracted and pooled using established methods. Pain, fear, and distress were considered critically important outcomes. Results: Twenty-two studies were included; 2 included adolescents. Findings showed no benefit of false suggestion (n=240) for pain (standardized mean difference [SMD] -0.21 [-0.47, 0.05]) or distress (SMD -0.28 [-0.59, 0.11]), or for use of repeated reassurance (n=82) for pain (SMD -0.18 [-0.92, 0.56]), fear (SMD -0.18 [-0.71, 0.36]), or distress (SMD 0.10 [-0.33, 0.54]). Verbal distraction (n=46) showed reduced distress (SMD -1.22 [-1.87, -0.58]), but not reduced pain (SMD -0.27 [-1.02, 0.47]). Similarly, video distraction (n=328) showed reduced distress (SMD -0.58 [-0.82, -0.34]), but not reduced pain (SMD -0.88 [-1.78, 0.02]) or fear (SMD 0.08 [-0.25, 0.41]). Music distraction demonstrated reduced pain when used with children (n=417) (SMD -0.45 [-0.71, -0.18]), but not with adolescents (n=118) (SMD -0.04 [-0.42, 0.34]). Breathing with a toy (n=368) showed benefit for pain (SMD -0.49 [-0.85, -0.13]), but not fear (SMD -0.60 [-1.22, 0.02]); whereas breathing without a toy (n=136) showed no benefit for pain (SMD -0.27 [-0.61, 0.07]) or fear (SMD -0.36 [-0.86, 0.15]). There was no benefit for a breathing intervention (cough) in children and adolescents (n=136) for pain (SMD -0.17 [-0.41, 0.07]). Conclusions: Psychological interventions with some evidence of benefit in children include: verbal distraction, video distraction, music distraction, and breathing with a toy.