Background <p>Lymphomas in children and adolescents accounted for about 25% of all lymphoma cases. The cancer-specific death (CSD) of children and adolescent-onset remains dismal and varies widely in different individuals. The current investigation aimed to develop a predicting nomogram to evaluate CSD risk in children and adolescents‑onset lymphoma with data from the Surveillance, Epidemiology and End Results (SEER) database.</p> Methods <p>The pathological variables of lymphomas patients were extracted from the SEER database. A competing risk model was used to identify independent factors for CSD. The predicting nomogram was also developed. The performance of the nomogram was evaluated with calibration curves, receiver operating characteristic curve and decision curve.</p> Results <p>A total of 7349 lymphoma cases were selected in our investigation, which were separated into the training (<i>n</i> = 5144) and testing (<i>n</i> = 2205) cohorts. The results of univariate and multivariate analysis demonstrated age, race, year of diagnosis, pathological subtype, tumor grade, tumor stage, and chemotherapy as independent risk factors for CSD in lymphoma cases. The 1-year, 3-year-, and 5-year AUCs of ROC curves of nomogram for CSD in lymphoma were 0.855, 0.827, and 0.810 in the training cohort and 0.862, 0.829, and 0.812 in the testing cohort, respectively. Further analysis suggested a good agreement between the observed outcome and the predicted probabilities in the calibration curves in training cohort and testing cohort. Moreover, decision curve analysis also indicted good clinical utility of the nomogram models in training cohort and validation cohort.</p> Conclusion <p>The nomogram shows good accuracy and reliability in evaluating the risk of CSD in children and adolescents‑onset lymphoma, and it could provide some theoretical support for clinicians to make decisions.</p>