Respiratory diseases impose a big global health burden. Around 65 million people have moderate to severe chronic obstructive pulmonary disease (COPD), from which about 3 million die each year. Chest diagnostic imaging is vital in managing a critically ill patient. Right now, direct visualization of the lung parenchyma is done using a chest x-ray (CXR) and computed tomography (CT), with the patient in the supine position in the Intensive Care Unit (ICU). Aims & Objectives: To assess the efficacy of BLUE protocol in diagnosing patients with respiratory failure in intensive care unit. To evaluate the USG findings among study participants and to compare the USG Diagnosis and CT Diagnosis of Patients. Methodology: This was a hospital based cross-sectional, descriptive, prospective study conducted among 150 patients who were admitted into ICU at NRI Medical College suspected with Acute Respiratory Failure in a period of 18 months. Patients admitted to the ICU with respiratory failure were tested initially using LUS and BLUE protocol without interrupting other management. Final diagnosis was done based on history, clinical examination, CT scan, CXR, clinical progression under treatment, and evaluation of cardiac function using echocardiography, functional tests. Data was entered on a Case record form and was represented as frequency and simple percentages. Data analysis was done using Microsoft excel 2019 and IBM SPSS software version 23.0. Sensitivity, specificity, NPV and PPV were calculated for BLUE Protocol using CT diagnosis. Results: A total of 150 patients who were admitted into ICU with various respiratory disorders were evaluated in this study. The age of patients involved in this study ranged from 21-70 years with mean age of 52.27 years. The most common organism isolated was E Coli. Most of the patients had Pneumothorax in the current study. Accuracy was 90.48% in diagnosing pulmonary edema using USG in ICU. Conclusions: LUS is a multifaceted option with low radiation doses for ARF management in critical care settings. LUS is an accurate method for diagnosing pneumothorax, alveolar- interstitial syndromes, parenchymal consolidations, pleural effusion.