Hormonal assessment including luteotropic hormone (LH), follicle stimulating hormone (FSH), testosterone (T), oestradiol and sex hormone binding globulin was performed 1-6 years after allogeneic, syngeneic and autologous bone marrow transplantation in nine patients with severe aplastic anaemia (SAA) and 14 patients with haematological malignancy (HM). Among nine allografted SAA patients, seven aged less than 26 years showed normal gonadal function while two women above 26 years had premature ovarian failure. All eight female patients transplanted for HM had premature ovarian failure. Among six male patients transplanted for HM, four have elevated FSH but normal LH and T levels, while two have normal LH, FSH and T levels or elevated LH and FSH levels but decreased T levels, respectively. Three patients transplanted for SAA (two female, one male), but none of those transplanted for HM, parented four healthy children. A high incidence of offspring complications was noticed, including (i) persistence of fetal circulation syndrome, (ii) erythroblastosis fetalis, and (iii) prolonged newborn icterus. One female patient transplanted for SAA had an abortion in the 25th week of gestation. These observations confirm previous reports on recovery of fertility, mainly in younger patients transplanted for SAA; there was, however, an unexpectedly high incidence of pre-, peri- and postpartum complications in the offspring of bone marrow graft recipients.