Spirometry is the ideal evidence to diagnose and evaluate the degree of bronchial obstruction which is present in asthma; however, it is not easy for physicians to have access to it during the first contact due to its high cost. The Borg's scale is an analogous visual scale which has an economical and simple use; it evaluates in a subjective way the respiratory difficulty in a patient in a scale from 0 to 10. It is necessary to have the right tools to know the degree of pulmonary obstruction that asthmatic patients have and to be able to give them the right medical treatment. The use of the Borg's scale to evaluate the severity of the asthmatic patients causes controversy.To determine the correlation between the spirometry and the Borg's scale in adult asthmatic patients.One hundred and one cases of male and female asthmatic patients were studied (GINA2002) from the consultation of specialties in Allergy and Clinic Immunology. A spirometry was done to all patients (Multispiro 2000) and the Borg's scale method was applied to them. The project was approved by the local research committee. The SPSS program version 12.0 was used and the Pearson's correlation test was applied.The correlation between the spirometry and the Borg's scale was r = 0.345, with p < 0.05.There is a scarce correlation between the spirometry and the Borg's scale. The result obtained in this study does not support the use of the Borg's scale to appreciate the bronchial obstruction in adult asthmatic patients.