BACKGROUND The clinical history taking and physical examination are the hallmarks of medical teachings and in clinical practice. However in present days these traditional methods are losing their importance due to availability of advanced technologies. The clinicians are more dependent on the investigations. History and clinical examination, till recent times were thought to be less objective and individualized. But there are statistical parameters based on evidence based medicine and clinical care that can be used to make the clinical examination more objective and precise. Utilizing these parameters the clinical examination will be more beneficial to the clinicians. In resource limited settings, clinical examination combined with the following statistical parameters will help to narrow down the diagnosis and provide timely diagnosis. The article tries to give a template for predicting the probability, establishing treatment and testing thresholds for common respiratory symptoms based on the evidence based medicine methods.