In the etiopathogenesis of bronchial asthma, the important role of bacterial infection is more evident every day, favoring inflammation and obstruction, that is, triggering an asthmatic response. We gathered 36 patients diagnosed of bronchial asthma with sensitization to Dermatophagoides pteronyssinus and 32 healthy subjects. Histamine release tests against Staphylococcus aureus extract alone or together with D. pteronyssinus were performed, and the results were contrasted with or without the presence of S. aureus in the nasal secretion culture. We found histamine release against S. aureus higher than 10% only at the highest concentration (200 micrograms/ml) and significantly higher in those patients with positive nasal secretion culture. Regarding histamine release against D. pteronyssinus in the presence of S. aureus, we found a release by coincubation significantly higher than the one obtained from the addition of release against S. aureus and release against D. pteronyssinus, both in patients with negative and with positive nasal culture, at concentrations of 20 and 2 micrograms/ml. In conclusion, we observed a potentiation of histamine release against D. pteronyssinus with S. aureus extract in patients with bronchial asthma. These findings support the important role of the bacterial infection in the etiopathogenesis of bronchial asthma and the importance of a treatment against this infection.