BACKGROUND Achromobacter xylosoxidans is an aerobic, motile, Gram-negative, opportunistic pathogen that can be responsible for various severe nosocomial and community-acquired infections. It has been found in immunocompromised patients and patients with several other underlying conditions, but the clinical role of this microorganism in cystic fibrosis is unclear. CASE REPORT We describe a case of septic shock caused by A. xylosoxidans in a 10-year-old child with cystic fibrosis and severe lung disease. CONCLUSIONS As the prevalence of A. xylosoxidans in cystic fibrosis patients is rising and patient-to-patient transmission is highly probable, further studies are warranted to determine its role and to document the appropriate treatment strategy for eradication and long-term treatment of this organism.