OBJECTIVE: To examine the association of psychological factors and pediatric health care utilization. METHOD: Ovid Medline and PsychInfo were searched and archival and forward searchers were conducted of relevant articles. Studies of the association between psychological risk factors and pediatric health care utilization of outpatient services, emergency department, inpatient length of stay, and costs were identified. Effect sizes were expressed in the form of the standardized mean difference. From 4,546 studies identified in the search, 69 studies met inclusion criteria. RESULTS: There were significant low-moderate associations between higher outpatient visits and general child mental health (MH) problems (mean ES [mES] = 0.35), overall psychopathology (mES = 0.44), and internalizing symptoms (mES = 0.16). Results were significant for any parent MH problem (mES = 0.18). For emergency department (ED) visits, there were significant association between more ED visits and any child MH problems (mES = 0.25), internalizing symptoms (mES = 0.24), externalizing symptoms (mES = 0.16), and Attention Deficit/Hyperactivity Disorder (mES= 0.14), as well as parent MH (mES = 0.24) and maternal depression (mES = 0.21). Increased hospitalizations were associated with any child MH problem (mES = 0.3), overall child psychopathology (mES = 0.49), child depression (ES = 0.41), and any parent MH problem (mES = 0.54). For costs, results were significant for any child MH problem (mES = 0.38). CONCLUSIONS: Child and parent MH problems are significantly associated with increased HCU.