Some patients suffering from malignancies may benefit of myeloablative chemotherapy followed by hematological reconstitution with autologous peripheral blood reinfusion. A quick evaluation of the number of hematopoietic progenitors present in leukapheresis blood samples is necessary to ensure the collection of a sufficient number of these cells. A study was performed on a series of 25 leukapheresis following initial chemotherapy. The number of granulomonocytic colony-forming unit (CFU-GM) and the number of CD34+ cells were evaluated simultaneously, in each sample. Results have shown a relatively strong linear correlation between both methods of evaluation of hematopoietic progenitors, suggesting that immunophenotyping could be a useful method to estimate the number of progenitors.