Pulmonary Tuberculosis (TB) is a rare infectious complication after Hematopoietic Stem Cell Transplantation (HSCT), and may have different prognosis and clinical characteristics. Etiological basis of TB after HSCT is often difficult to discover, leading to difficulties in diagnosis. Here, we present two patients who were diagnosed with pulmonary TB after HSCT. One patient had non-Hodgkin's lymphoma, and was diagnosed with pulmonary TB four months after autologous peripheral HSCT. Another patient had acute lymphoblastic leukemia, and was diagnosed with pulmonary TB two months after unrelated allogeneic HSCT. Both of the two patients received anti-TB treatments. The patient with non-Hodgkin's lymphoma responded well to anti-TB treatment. However, the other patient with acute lymphoblastic leukemia died of TB ultimately, because that his condition was complex and the disease progressed rapidly. Based on these two cases, we review some articles and discuss the clinical characteristics, diagnosis and treatment of patients who are infected by TB after HSCT. Patients with hematologic diseases after HSCT have compromised immunity and are easy to have a variety of infections. Among the infections, TB infection is atypical in these patients, and it is often difficult to find the reason based on etiology. Of note, the diagnosis and treatment of TB infection are often delayed and difficult.