Bronchial asthma is a chronic inflammatory disorder of the airways characterized by airway hyper responsiveness and reversible airflow obstruction that fluctuates over time. Parasitic infection is one of the environmental factors associated with a small increase in bronchial asthmatic risk. In the present study, 200 stool samples were collected from patients suffering from bronchial asthma and 200 stool samples from non-asthmatic healthy volunteers as control group. The samples were preserved in 10% formalin and examined macroscopically, microscopically by direct smear & formol ether sedimentation techniques. It was found that 12/200 cases (6%) were infected with Ascaris lumbricoides in asthmatic group and 2/200 cases (1%) in control (P = 0.007) illustrating significant difference between cases and control group indicating a role of Ascaris lumbricoides as a risk factor for bronchial asthma.