Achromobacter xylosoxidans is an aerobic, Gram-negative rod with a broad intrinsic and acquired antimicrobial resistance, usually isolated in patients with cystic fibrosis (CF), immunodeficiencies, or those undergoing invasive procedures. We report a case of a previously healthy 14-year-old girl who was hospitalized in our institution due to a prolonged, progressive cough and exertional dyspnea, which started after a mild viral respiratory tract infection. To elucidate the cause of her symptoms, a bronchoscopy was finally performed, showing bilateral purulent bronchitis caused by A. xylosoxidans, isolated from bronchoalveolar lavage (BAL) sample. Since the patient had positive serological testing for coronavirus disease 2019 (COVID-19), we concluded that it was the initial viral infection, although of a mild clinical course, the one that created favorable conditions for proliferation and further inflammation caused by A. xylosoxidans.