Autologous bone marrow transplantation (ABMT) allows application of intensive myeloablative therapy aimed at eradication of neoplastic disease by facilitating haematopoietic reconstitution. Between March and June 1988, four patients (two with acute myelogenous leukaemia in first remission, one with acute lymphoblastic leukaemia in second remission, and one with Burkitt lymphoma, stage IV with CNS involvement in second remission) received this treatment. Methods of collecting, processing and freezing bone marrow as well as thawing and reinfusion of the marrow into patients after intensive chemoradiotherapy are described. Viability of bone marrow cells tested by the dye exclusion method after freezing and thawing process was 89, 88, 91 and 78%, respectively. CFU-GM recovery in culture, as a test of marrow stem cells clonogenicity was between 63,3 and 156,5%. Patients received between 1,7 and 3,0 x 10(8)/kg nucleated cells and 4,0 to 7,6 x 10(4)/kg CFU-GM, respectively. In all four patients stable haematopoietic reconstitution was achieved. The bone marrow function was evident mainly at 11th day after marrow reinfusion. Leukocyte count reached 1,0 x 10(0)/L in 11 to 15 days, and granulocyte count raised more than 0,5 x 10(9)/L in 19 to 37 days after transplantation. Platelet recovery was prolonged with the minimum of 29 days and maximum of more than 60 days to reach 20 x 10(9)/L. Side effects caused by the intensive radiochemotherapy were moderate. Bacterial, fungal and viral infections in early posttransplant period were successfully treated. All patients have survived and left the hospital 63, 54, 36 and 65 days after ABMT, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)