OBJECTIVES: The main objectives of this study were to: 1) Estimate the economic costs associated with opioid poisonings and 2) Examine the characteristics associated with opioid poisoning-related costs in children. METHODS: Economic costs were estimated using the 2012 Nationwide Emergency Department Sample, Kids’ Inpatient Database, Multiple Cause-of-Death file and other published sources, applying a societal perspective. Direct costs included costs associated with emergency department (ED) visits, hospitalizations and ambulance transports. Indirect costs included productivity costs due to caregivers’ absenteeism and premature mortality among children. Markov chain Monte Carlo analysis was used to impute missing costs and sensitivity analyses were performed. A generalized linear model with a log-normal distribution was used to estimate the association of sociodemographic, clinical, payer and hospital characteristics with ED and inpatient costs. RESULTS:  Total economic costs of pediatric opioid poisonings in the United States were calculated at $230.8 million in 2012. Total direct costs were estimated to be $21.1 million. Total productivity costs were calculated at $209.7 million, and 98.6% of these costs were attributed to opioid poisoning-related mortality. There were a total of 4,584 ED visits, 1,877 hospitalizations and 123 deaths related to opioid poisonings in children. Mean costs for pediatric opioid poisoning-related ED visits and hospitalizations were estimated at $1,289 (SE = 54) and $6,633 (SE = 630), respectively. Teenagers had 1.39 (95% CI: 1.15-1.68) times higher ED costs compared to ≤6 year olds. Inpatient costs were significantly higher among children with higher median household income, moderate-to-extreme loss of function, post-discharge transfer, and private insurance. CONCLUSIONS: Opioid poisonings in children resulted in direct and indirect costs of $230.8 million in 2012. Quantified healthcare costs associated with pediatric opioid poisonings can help decision-makers understand the economic trade-offs in planning interventions.