Background: Pulmonary edema is a medical emergency that threatens life, and requires urgent management and immediate hospitalization. Since there is no definite "gold standard" for diagnosing ALI/ARDS or cardiogenic pulmonary edema (CPE), there is no technique or known biomarker that can be used to distinguish between the two conditions. Combining clinical criteria with other proven diagnostic methods, such as BNP and chest ultrasonography, can increase the predicted accuracy, assist in therapy, and enhance the results. Objective: The purpose of this study is to assess how well plasma brain natriuretic peptide (BNP) and chest ultrasonography can distinguish between cardiogenic and noncardiogenic pulmonary edema. Patients and methods: Lung US was applied to respiratory distressed patients In Benha University Hospital Chest ICU and Emergency Department on 50 subjects through a cross-sectional prospective study. They were divided into CPE group 20 cases) and NCPE group (20 cases) as well as the control group (10 cases). Alveolar-interstitial syndrome (AIS), absence or decreased lung sliding, sparing regions, subpleural consolidation, pleural line abnormalities, and pleural effusion were among the pleuropulmonary symptoms that were targeted for detection by the LUS scan in both groups. Plasma BNP levels were assessed in all groups. Results: Consolidation is another sonographic finding in the Non-CPE group which represents 80% of cases and is present in 5% only in the CPE group in our study. Pleural effusion is not a specific finding between the two groups but it was higher among the cardiogenic group representing 65% while was 25% only among the non-cardiogenic group. BNP was significantly higher in the CPE group (1031 pg/ml) than in the Non-CPE group (346.5 pg/ml) and controls (63.5 pg/ml) (P <0.0001). BNP was valid for differentiation between CPE and non-CPE with a Cutoff point of >740 pg/ml (70% Sensitivity and 100% Specificity). Conclusion: CUS in combination with BNP represents a useful tool for differentiating CPE from non-CPE. In emergency settings, the benefits of their use outweigh the presence of limitations.