A 55-year old woman with multiple myeloma was treated with hematopoietic stem cell transplantation (HSCT). She developed cutaneous and hepatic graft-vs-host disease (GVHD). Sixty-five days after HSCT, acute respiratory failure occurred. A thoracic computed tomography scan showed bilateral patchy infiltrates. Bronchoalveolar lavage revealed 40% eosinophils on differential cell count with no infectious pathogens. These findings were in favor of acute eosinophilic pneumonia. High-dose steroid treatment was started, which had a rapid and lasting favorable course. After HSCT, clinicians should be aware that acute eosinophilic pneumonia mimics infectious pneumonitis and can be associated with GVHD.