Objective: To examine whether hospital-level factors contribute to discrepancies in reporting to child protective services (CPS) of infants diagnosed with prenatal substance exposure. Study design: We used a linked dataset of birth, hospital, and CPS records using diagnostic codes (ICD-9) to identify infants diagnosed with prenatal substance exposure. Employing multilevel models, we examined hospital-level and individual birth-level factors in relation to a report to CPS among those infants prenatally exposed to substances. Results: Of the 760,863 infants born in Washington State between 2006 and 2013, 12,308 (1.6%) were diagnosed with prenatal substance exposure. Infants born at hospitals that served larger populations of patients with Medicaid (OR: 1.25, 95% CI: 1.07, 1.45) and hospitals with higher occupancy rates (OR: 1.43, CI: 1.15, 1.77) were more likely to be reported to CPS. Infants exposed to amphetamines (OR: 2.58, CI: 2.31, 2.90) and cocaine (OR: 2.33, CI: 1.92, 2.83) were more likely to be reported and infants exposed to cannabis (OR: 0.62, CI: 0.55, 0.70) were less likely to be reported to CPS than infants exposed to opioids. Infants with Native American mothers were more likely to be reported to CPS than infants with white mothers (OR: 1.47, CI: 1.27, 1.70). Conclusions: Hospital-level and individual birth-level factors impact the likelihood of infants prenatally exposed to substances being reported to CPS, providing additional knowledge about which infants are reported to CPS. Targeted education and improved policies are necessary to ensure more standardized approaches to CPS reporting of prenatal substance exposure.