Asthma is a chronic respiratory disease characterized by hypersensitivity and inflammation of the airways with clinical symptoms of dyspnea, wheezing, coughing, reversible episodes of bronchoconstriction, shortening of breath, chronic eosinophilic inflammation, mucus hypersecretion and tightening of the chest [1, 2]. The exacerbation of asthma symptoms and the level of asthma severity have shown to be related to genetic susceptibilities to exposure to various environmental triggers . Inflammatory triggers of asthma include pets, dander, dust, mold, pollen, and viral respiratory infections and non-inflammatory triggers include tobacco smoke, exercise, weather changes, stress, and air pollution [4, 5]. The contribution of viral infections to the occurrence of asthma exacerbations has been of broad interest for the past 20 years . In this regard, it is believed that viral respiratory tract infections with respiratory syncytial virus and rhinoviruses are the major causes of acute asthma exacerbations in children [7–10]. Besides, the involvement of coronaviruses (hCoV) in asthma exacerbation has been recently revealed with the implementation of molecular methods. coronaviruses are enveloped, with a single stranded RNA, linear, non segmented and positive sense genome. These viruses are divided into 3 distinct genera (genus Alpha, Beta and Gamma coronavirus). So far, five types of human coronaviruses including HCoV-OC43 (mid-1960s), HCoV-229E (mid-1960s), SARS-CoV (2003), HCoV-NL63 (2004) and HCoV-HKU1 (2005), have been described . The involvement of coronaviruses in asthma exacerbation has recently been revealed with the implementation of molecular methods such as the reverse transcriptase polymerase chain reaction (RT-PCR) . Here, we report the first case of an asthma exacerbation triggered by acute pharyngitis event in a child caused by HCoV-HKU-1 infection.