The pandemic influenza A H1N1 will affect millions of subjects. This influenza can cause respiratory complications with possible death. We have described two case reports of acute severe asthma exacerbation combined to influenza A H1N1, caracterized by severe respiratory failure. The diagnosis of influenza A H1N1 was confirmed with the multiplex reverse transcription-polymerase chain reaction (RT-PCR) assay. These patients, apart from asthma, do not have other diseases; but they did not take adequate therapy. In addition to conventional therapy (corticosteroids, bronchodilator and antibiotics) oseltamivir 75 mg bid was immediately added. After few days the patients improved and therefore in a short time they were discharged. During this period, in the case of severe asthma exacerbations, one must always think of influenza A H1N1 as the possible cause. It is necessary to use oseltamivir precociously to avoid severe complications. All asthmatic patients must regularly take their therapy especially during pandemic influenza A H1N1.