BACKGROUND: Determine the predictive value of brain magnetic resonance imaging (MRI) findings less than or equal to seven days post-pediatric out-of-hospital cardiac arrest (OHCA) for long-term outcomes. METHODS: This retrospective single-center study included children (zero to 17 years) with OHCA admitted to a tertiary care hospital pediatrc intensive care unit from 2012 to 2020 who underwent brain MRI at most seven days postarrest. A neuroimaging scoring system was designed, using T1-, T2-, and diffusion-weighted images based on previously published scores and brain injury patterns. Extensive brain injury was defined as ≥50% cortex/white matter injury or four or more of nine predefined brain regions. Pediatric cerebral performance category (PCPC) scores were determined at hospital discharge and two years post-OHCA as part of routine follow-up care. Favorable neurological outcomes were defined as PCPC scores of 1 to 2 or no change from prearrest status. RESULTS: Among 142 children, 56 had a brain MRI at less than or equal to seven days postarrest. Median arrest age was 3.3 years (first and third quartiles [Q1, Q3]: 0.6, 13.6), and 64% were male. Brain MRI was obtained four days post-OHCA (Q1, Q3: 3, 5). Normal brain MRI findings (i.e., negative test result) predicted favorable outcomes with 100% negative predictive value, whereas extensive injury (i.e., positive test result) predicted unfavorable outcomes and death with 100% positive predictive value. CONCLUSIONS: A normal brain MRI at less than or equal to seven days postarrest predicts favorable neurological outcomes two years later, whereas extensive brain injury predicts unfavorable neurological outcomes or death at discharge and two years post-OHCA.