Objective. Asthma life quality (ALQ) test has been used in many countries for the diagnosis of asthma and it has been proved to be useful also. The present study aimed to validate the ALQ test for the positive diagnosis of asthma and to assess its severity. Methods. Two hundred doctor-diagnosed bronchial asthma patients and 200 control subjects were studied. Standard form of ALQ test was used. Patients with bronchial asthma were categorised into mild-to-moderate and severe asthma categories. Receiver operating characteristic curve was plotted to determine the cut-off for ALQ score to assess the severity of asthma among adults in Delhi. Results. The mean (± standard deviation) values for ALQ score were higher in patients with asthma compared to control subjects (15.0±3.9 versus 0.7±0.9; p<0.001). Significantly higher mean ALQ score was seen in patients with severe asthma compared to those with mild-moderate asthma compared to those with severe asthma (18.1±2.0 versus 13.1±3.5; p<0.001). At a cut-off value of 16.5, ALQ had a sensitivity of 79% and specificity of 84%, area under curve was 0.887 (p<0.001) for the diagnosis of severe asthma. Conclusions. Asthma life quality test appears to be a useful tool to diagnose and assess severity of bronchial asthma.