Authors report a case of beta thalassemia combined with hematological malignant (ATLL) in a 40-year-old female, cashier screened HTLV-1 positive; followed since her 10 years old for the account of thalasso-sickle cell disease at the adult referal center of sickle cell disease in Martinique. Therapeutic management consisted of systemic chemotherapy, intrathecally-administered preventive chemotherapy combined with a treatment based on bisphosphonate and corticosteroid.