All-trans retinoic acid (ATRA) is currently being used as remission induction treatment for acute promyelocytic leukemia (APL). Conventional chemotherapy is added both during and after ATRA treatment, in order to avoid the occurrence of hyperleukocytosis, and to improve the duration of complete remission. In this study we analysed the hematopoietic recovery of 18 consecutive APL patients after standard Idarubicin or Daunorubicin +/- Cytosine-Arabinoside regimens. 9 of the patients were at the onset of the disease, (CHT group) while 9 had been pre-treated with ATRA 45 mg/sqm/day for at least 3 months (ATRA group). 500 PMN/mmc were reached after 20.8 day from the end of treatment in CHT group and after 12.0 days in ATRA group (p = 0.007). Platelets recovery was faster, even though not significantly in ATRA group. Interestingly, PMN recovery in ATRA group was even shorter (p = 0.004) than that obtained in CHT group, after the first course of chemotherapy (treatment in CR vs treatment in CR). If these results are confirmed in a larger study, a protective effect of ATRA on normal residual hemopoiesis should be postulated.