Background <p>Severe pneumonia (SP) poses a serious threat to patients’ lives, and this study aimed to explore the diagnostic and prognostic value of miR-193b-3p on SP, thereby providing novel insights for the clinical management of SP.</p> Methods <p>The miR-193b-3p expression was evaluated by PCR. The diagnostic value of miR-193b-3p on SP was assessed by ROC. The association between miR-193b-3p expression and the SP severity was assessed by the correlation analysis. The correlation between miR-193b-3p expression and the survival status of SP patients was evaluated by the Kaplan-Meier survival analysis. Potential independent prognostic factors for SP were predicted by multivariate COX regression analysis. Bioinformatics analysis assessed the possible pathways regulated by miR-193b-3p.</p> Results <p>Upregulation of miR-193b-3p in SP patients showed a diagnostic value in SP. The miR-193b-3p expression was positively correlated with the levels of WBC, NEU, CRP, PCT, BNP, and D-D, and negatively correlated with LYM. The expression level of miR-193b-3p was significantly associated with the APACHE-II and CPIS scores, and a better survival rate was observed in SP subjects with low miR-193b-3p expression levels. MiR-193b-3p, together with CRP, PCT, APACHE-II, and CPIS, could also serve as independent prognostic factors for SP. MiR-193b-3p was associated with PI3K-Akt, MAPK, FoxO, TRP channel, and Wnt signaling pathways.</p> Conclusion <p>Upregulated miR-193b-3p expression in SP patients had a diagnostic and prognostic value for SP.</p>