Dengue fever is endemic in tropical and subtropical countries. Dengue virus transmission through hematopoietic stem cells is very rare and just two such cases have been reported previously. We report here only third case of dengue virus transmission in a 2-year-old child with thalassemia major who underwent hematopoietic stem cell transplant (HSCT) from a haploidentical related donor. One week after HSCT, the recipient developed fever, pancytopenia and signs of capillary leak. On day 10, his dengue NS1 antigen test was positive which confirmed diagnosis of dengue fever. Donor also had fever few days prior to stem cell donation which was later diagnosed to be due to dengue fever. Child had a severe clinical course of dengue leading to primary graft failure. However, he had autologous recovery of his own bone marrow and is alive and well on day+200 post HSCT. Our report highlights the transmission of dengue virus from donor to recipient through hematopoietic stem cell graft although rare but possible. We suggest that in tropical and subtropical countries where dengue is endemic, hematopoietic stem cell donors should be screened for it.