Radiation and chemotherapeutic drugs for cancer produce prolonged and often irreversible gonadal damage. To determine whether total body irradiation (TBI)-induced gonadal damage can be prevented by suppression of pituitary gonadotrophin levels, we studied a patient with transfusion dependent homozygous beta-thalassaemia and acute lymphoblastic leukaemia (ALL) who underwent one-antigen mismatched related bone marrow transplantation (BMT). Our data showed that despite having hypogonadotrophic hypogonadism (HH) prior to BMT, the patient developed primary testicular failure following the procedure, indicating that hypogonadotrophism failed to offer protection against TBI-induced testicular damage in this patient. Although this is an interesting case report, no firm conclusions can be drawn from a single patient.