Cell viability and number of granulocyte-monocyte colony forming units (CFU-GM) were systematically assessed in 57 patients who had undergone transplantation of the autologous bone marrow for treatment of haematologic malignancies. Bone marrow cell cultivation in agarose with feeder layers appeared inferior to that performed in agarose with recombinant human granulocyte-monocyte colony stimulating factor and methylcellulose with phytohaemaglutinin leukocyte-conditioned medium. Since the transplant cells were frozen in liquid nitrogen between harvesting and reinfusion, the following samples were tested: buffy coat cells, buffy coat cells immediately after addition of dimethylsulphoxide, cell sample that had been frozen for 24 hours, and frozen transplant cells at the time of thawing and transplantation. Each procedural step decreased both cell viability and the number of CFU-GM, but since the lymphohaematologic recovery in all patients followed the pattern reported in the literature for high-quality transplants, we concluded that our transplants retained the necessary number of progenitor cells. It appears that the best strategy for dynamic assessment of the transplant quality would be to perform tests after every step of the transplant processing. Cell viability and number of progenitors per body weight in transplants were also found to be associated with probability of neutrophil reconstitution after bone marrow reinfusion.