Background: Preliminary research has shown that pulmonary ultrasonography (PU) has become a vital tool for quickly diagnosing the cause of acute respiratory failure (ARF), as well as monitoring therapy progress in critically sick patients. The aim of the present study is to examine the relationship between the PU grading system and clinical metrics to identify the etiology of ARF with assessment of treatment response. Patients and methods: A prospective cohort study of 50 ARF patients was recruited from Benha University Hospital's respiratory, general, and coronary critical care units. PU examinations were performed at 3 time points during a patient's ICU stay at intubation, 48 hours after intubation and after extubation. Results: The research comprised 28 men and 22 women. The average age of participants was 58 years old. COVID-19 was the most common diagnosis (46%). Average intubation was 6.42 days, with a P/F ratio of 172.14 and average length of stay in the ICU 10.06 days. The average length of stay in the hospital was 12.6 days, with death rate 68%. Mean first US score was 18.1 and second US score 17.54. The first total US score had a substantial positive association with mortality rate. The initial total US score had also a substantial positive link with the length of ICU stay and ventilation days (p < 0.001), whereas the P/F ratio had a negative correlation with the total lung score (p < 0.001). Conclusion: First-to-total US score had positive connection with mortality, length of hospital stay, length of ICU stays, ventilation days, and negative connection with P/F ratio.