Pneumonia is the most common cause of death in younger children (<5 years of age) in developing countries, and early diagnosis and intervention are effective in reducing mortality. Chest X-ray is the gold standard for the diagnosis of pneumonia. However, in resource-poor areas, not all children with cough are willing to undergo a chest X-ray due to the economic burden and potential side effects of radiation exposure. Predictors that help identify children who should receive antibiotics or chest X-rays are therefore important. Currently, pneumonia diagnostic criteria in developing countries are still based on the WHO recommendations of cough, tachypnea, and chest depression from the 1980s, and these pneumonia diagnostic criteria have not been significantly updated in decades, and there are no immediate tests with high accuracy to identify children who should receive antibiotics. Professor Althaus et al from Switzerland evaluated the diagnostic value of clinical predictors of radiation pneumonitis in children <5 years of age by searching Medline (PubMed), Embase (Ovid), and the Cochrane Database of Systematic Evaluation, as well as references to related studies, and the results were published in a recent issue of Lancet Infect Dis. A total of 18 studies were included in the analysis through screening. The most commonly evaluated studies included: tachypnea, chest wall depression, nasal flutter, elevated temperature, twitching, history of fever, and wheezing. Findings 1. The diagnostic accuracy of age-related tachypnea and low chest wall depression was not high among the WHO published diagnostic indicators for pneumonia. 2. 2. Characteristics strong enough for a diagnosis of pneumonia are: a respiratory rate higher than 50 breaths/minute, a whistling groan, low chest wall depression, and nasal flaring. 3. One clinical feature alone is not sufficient to diagnose pneumonia. When establishing the diagnosis, the combination of the best clinical signs and symptoms improves the overall diagnostic accuracy. 4. In the diagnosis of bacterial pneumonia, some immediate tests can help to improve the diagnostic accuracy, but these new immediate tests still need to be researched and explored. 5. It is necessary to investigate the clinical prognosis of children with acute respiratory tract infections, whether or not they receive antibiotics, in order to accurately determine whether or not these patients really need antibiotic treatment, which is also an effective way to reduce antibiotic abuse.