OBJECTIVE To investigate the value of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and red blood cell distribution width (RDW) in evaluating the prognosis of children with severe pneumonia (SP). METHODS A retrospective analysis of the data of 91 children with SP admitted to our hospital from March 2018 to March 2021. According to the survival status after 28 days of treatment, all children were divided into the survival group (n = 59) and the death group (n = 32). The clinical data and laboratory indicators of the patients were recorded. Multivariate logistic regression was used to analyze the risk factors of prognosis, and the ROC curve was used to analyze the predictive value of each index. RESULTS The Acute Physiology and Chronic Health Evaluation II (APACHE II) score and CURB-65 score of the death group were higher than those of the survival group (P < 0.05). The RDW, NLR, PLR, and high-sensitivity C-reactive protein, procalcitonin blood lactic acid (Lac) of the death group, were higher than those of the survival group, and LYM was lower than the survival group (P < 0.05). Multivariate regression analysis showed that APACHE II score, RDW, NLR, PLR, and Lac were all independent risk factors for poor prognosis in children with SP (P < 0.05). The AUC of NLR, PLR, and RDW for evaluating the prognosis of children with SP were 0.798, 0.781, and 0.777, respectively. The sensitivity was 56.25%, 90.63%, and 56.25%, respectively, and the specificity was 89.83%, 55.93%, and 91.53%, respectively. The AUC of NLR, PLR, and RDW combined to evaluate the prognosis of children with SP was 0.943. When the best cut-off value was 0.8528, the sensitivity was 93.75%, and the specificity was 91.53%. CONCLUSIONS NLR, PLR, and RDW have certain predictive value for the prognosis of children with SP; the combination of the three indicators has a higher value in evaluating the prognosis of children with SP, which can better guide the prognostic treatment.