ABMT (autologous bone marrow transplantation) is being increasingly used in the treatment of malignant diseases, including the acute leukaemias. Although ABMT seems to be superior to conventional chemotherapy in terms of disease-free survival, an unacceptably high frequency of relapse after ABMT remains a major problem. As such relapse may be due to malignant cells in the graft or residual malignant cells surviving in the patient after preconditioning therapy, it is essential to be able to detect and eradicate residual malignant cells. The article presents a review of available methods for the detection of minimal residual disease in conjunction with ABMT, especially regarding their relative sensitivity and specificity.