Kaposi sarcoma (KS) is an angioproliferative disease associated with human herpesvirus 8 (HHV-8). We report the case of a 10-year-old male from a high HHV-8 prevalence area, diagnosed with severe aplastic anemia who underwent an upfront hematopoietic stem cell transplantation (HSCT). Five months after transplant, the patient was diagnosed with KS with skin, mucosae, lymph nodes and lung involvement. After withdrawal of immunosuppression the patient achieved complete remission without requiring further treatments. KS may occur after HSCT in patients from high HHV-8 prevalence areas. Considering that, we propose that screening of HHV-8 by antibody testing could be considered in HSCT donors/recipients from these areas.