Epstein-Barr virus (EBV) reactivation or infection after hematopoietic stem cell transplantation (HSCT) most often induces post-transplant lymphoproliferative disease (PTLD), but it also may be associated with clinical symptoms such as pneumonia. Our aim was to investigate and describe the clinical manifestations of PTLD and PTLD accompanied by EBV-associated pneumonia in 323 patients after HSCT. PTLD within extravisceral lymphoid tissue was identified in 7 cases (5 with CD20(+) diffuse large B-cell lymphoma, 1 with CD20(+) polymorphic B-cell hyperplasia, and 1 with CD3(+)CD45RO(+) peripheral T-cell lymphoma unspecified). Six of the patients with PTLD were EBV positive. Three patients had EBV-associated pneumonia, and chest computed tomography revealed multifocal patchy and diffuse ground-glass attenuation in both lungs. EBV-DNA was positive in bronchoalveolar lavage (BAL) fluid, which contained mainly CD3(+) T cells but no CD19(+) or CD20(+) B cells. Lung biopsy showed interstitial intra-alveolar infiltrates of mainly CD3(+) T cells and some CD68(+) macrophages without CD19(+) and CD20(+) B cells. The patients with PTLD accompanied by EBV-associated pneumonia developed hyperpyrexia and dyspnea, which progressed rapidly, and eventually all died within 2 weeks of the onset of PTLD. EBV-associated PTLD accompanied by EBV-associated pneumonia after HSCT is rare. Cytology of BAL fluid and lung biopsy may help establish the diagnosis.