Background/Aim. Discovering rapid and efficient biomarkers to predict the occurrence of acute respiratory distress syndrome (ARDS) is crucial for guiding subsequent treatment in patients with severe pneumonia (SP). The aim of this study was to determine the predictive value of the combination of the lung ultrasound score (LUS), the extravascular lung water index (EVLWI), and the C-reactive protein (CRP)/procalcitonin (PCT) ratio for predicting ARDS in patients with SP. Methods. The study included a total of 240 patients treated from January 2023 to January 2025, divided into two groups: a control group (n = 120) comprising patients with mild pneumonia and a research group (n = 120) comprising patients with SP. Comparisons of LUS, EVLWI, and CRP/PCT ratio were performed between the groups. The research group was further divided into an ARDS group (AG) and a non-ARDS group (N-AG). Results. Out of the 120 patients with SP, ARDS was registered in 20 (16.67%). The patients in AG exhibited significantly higher values of LUS, EVLWI, and CRP/PCT ratio in comparison to the N-AG patients (p < 0.05). In patients with SP, LUS, EVLWI, and CRP/PCT ratio positively correlated with the occurrence of ARDS (r > 0, p < 0.05) and were identified as independent risk factors for ARDS development (odds ratio > 1, p < 0.05). The areas under the receiver operating characteristic curve of LUS, EVLWI, CRP/PCT ratio, and their combination for predicting the occurrence of ARDS in patients with SP were 0.713, 0.739, 0.731, and 0.925 respectively (95% confidence interval: 0.867–0.983), with the combined model incorporating all three parameters showing the highest predictive performance. Conclusion. In patients with SP, LUS, EVLWI, and CRP/PCT ratio were elevated and were closely associated with the occurrence of ARDS.