Inflammation-based scores have been demonstrated to be independent prognostic factors in predicting outcomes in adult adrenocortical carcinoma (ACC). We aimed to investigate the prognostic role of these scores in pediatric adrenocortical carcinoma (pACC) patients. An international multicenter analysis was conducted on a pediatric cohort from 21 ACC centers. Pretreatment inflammation-based scoring parameters, including neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR) and serum albumin, as well as clinical parameters, were analyzed. The primary endpoint was 10-year overall survival (OS). One hundred twenty-nine pediatric patients (50.4% females, mean age 87 months) across all tumor stages with a median follow-up of 36 months were included. 107/108 patients underwent primary surgery, and 62/106 received systemic treatment at the time of diagnosis. Of 102 patients, 27 died from disease. In the univariable analysis, NLR ≥5 (HR 8.0, 95% CI 3.4–19.1), MLR ≥0.28 (HR 4.2, 95% CI 1.7–10.4), PLR ≥190 (HR 4.5, 95% CI 2.0–10.4) and dNLR ≥1.44 (HR 5.9, 95% CI 2.3–15.5), as well as clinical parameters age ≥4 years (HR 5.5, 95% CI 1.9–15.8), tumor stage IV (HR 5.7, 95% CI 2.7–11.9) and incomplete resection status (HR 8.0, 95% CI 3.6–17.7) were significantly associated with reduced 10-year OS. After multivariable adjustment, only tumor stage IV (HR 336.7, 95% CI 5.8–19,518.1) and MLR ≥0.28 (HR 247.1, 95% CI = 3.1–19,907.5) were significantly associated with an unfavorable outcome. Inflammation-based scores tend to have prognostic value in pACC and could serve as prognostic tools after further validation in future studies with sufficient case numbers.