Due to the expansion of cell therapy using not only haematopoietic stem cells (HSC) but also other leukocyte subpopulations, the loss of these cells in cryopreserved apheresis products needs to be evaluated. The primary aim of this prospective study was to evaluate the post-thaw recovery of HSC and leukocyte subpopulations using the flow cytometry 7-AAD and 7-AAD/annexin V methods. The secondary aim was to assess how the post-thaw recovery is affected by various parameters, and the third aim was to examine how the time of exposure to cryoprotective solution containing DMSO after thawing affects the sample stability and viability of HCS and leukocyte subpopulations in autologous and allogeneic PBSC samples. In samples of 30 autologous and 30 allogeneic PBSC products, the number of viable HCS, T and B lymphocytes, NK cells and monocytes was determined using the "single-platform" method. The stability of the samples post-thaw was tested at three points: immediately after thawing and one hour and three hours post-thaw. The lowest post-thaw recovery was observed in autologous and allogeneic for CD34+ cells. In leukocyte subpopulation, the lowest post-thaw recovery was observed for CD14+ cells, both autologous and allogeneic. The highest post-thaw recovery was observed for CD3+/CD8+ cells in autologous, and for CD19+ cells in allogeneic samples. The statistically significant difference was observed between autologous and allogeneic PBSC products for CD3+ cell recovery and CD3+/CD8+ cell recovery. The evaluation of factors that could adversely affect the post-thaw recovery in autologous samples showed weak negative correlations between platelet concentration and CD3+ recovery, as well as between storage time and CD3+CD8+ recovery. In allogeneic samples, a strong negative correlation was observed only between the percentage of granulocytes and CD3+, CD3+/CD8+ and CD3+/CD4+ cell recoveries. Analysis of the absolute count of viable cells in thawed samples showed a significant difference between all measurement points for CD34+, CD14+ and CD19+ cells. No significant differences were observed for post-thaw stability of allogeneic samples analysed between products stored before cryopreservation ≥ 24 hours (N=20), and those stored < 24 hours (N=10), except for viable CD3+/CD4+ cells after three hours post-thaw. Since various post-thaw recoveries of leukocyte subpopulations were observed, the cell therapy manufacturing centers should evaluate how their cryopreservation method and other factors affect the recovery of cell population of interest in their settings.