Noninfectious pulmonary complications are one of the major side effects of hematopoetic stem cell transplant (HSCT); however, the development of pulmonary sarcoidosis post-HSCT is uncommon, with only three cases previously reported. In each of those cases, sarcoidosis was also diagnosed in the stem cell donor. We now report four cases of de novo pulmonary sarcoidosis occurring post-HSCT (3 autologous HSCT and 1 allogeneic HSCT). We suggest that pulmonary sarcoidosis may develop following either autologous or allogeneic HSCT, and the prevalence may be 10-fold higher than that of the normal population.