Derber C et al. – Endocarditis due to Achromobacter species is a rare, yet serious, endovascular infection. Achromobacter species infective endocarditis is associated with underlying immunodeficiencies or prosthetic heart valves and devices. A case of prosthetic pulmonary valve endocarditis secondary to Achromobacter xylosoxidans subspecies denitrificans is described in the present report. This life–threatening infection was successfully treated with combined valve replacement and prolonged antibiotic therapy. Given the significant associated morbidity and mortality, along with a high degree of intrinsic antibiotic resistance, Achromobacter species infective endocarditis remains a clinical treatment challenge.