Obejctive To evaluate the impact of kinetics of molecular remission via retro transcriptase polymerase chain reaction (RT PCR) assay on the long term survival in patients with acute promyelocytic leukemia (APL) Methods Seventy patients with newly diagnosed APL in remission were involved in this study Monitoring of minimal residual disease (MRD) was performed regularly by RT PCR assay for PML RARα during consolidation Results A 5 year relapse free survival (RFS) and overall survival (OS) were estimated as 46 8%±8 4% and 69 9%±9 4% for the whole group Fifty two (74 3%) patients got negative RT PCR result at least once Serial monitoring of RT PCR was available in 38 cases and 24 (63 2%) patients presented with persistent negative PCR results The achievement and continuous negative RT PCR result was significantly related to the RFS Conclusions Achievement of negative RT PCR in remission is associated with favorable RFS and OS Continuous negative RT PCR results are associated with long term relapse free survival and may be considered as potentially curative RT PCR assay for detection of MRD should be performed regularly during post remission period as an important prognostic factor Obejctive To evaluate the impact of kinetics of molecular remission via retro transcriptase polymerase chain reaction (RT PCR) assay on the long term survival in patients with acute promyocyocytic leukemia (APL) Methods Seventy patients with newly diagnosed APL in remission were involved in this study Monitoring of minimal residual disease (MRD) was performed by RT PCR assay for PML RARα during consolidation A 5 year relapse free survival (RFS) and overall survival (OS) were estimated as 46 8% ± 8 4% and 69 9% ± 9 4% for the whole group Fifty two (74 3%) patients got negative RT PCR result at least once Serial monitoring of RT PCR was available in 38 cases and 24 (63 2%) patients presented with persistent negative PCR results The achievement and continuous negative RT PCR result was significantly related to the RFS Conclusions Achievement of negative RT PCR in remission is associated with favorable RFS and OS Continuous negative RT PCR results are associated with long term relapse free survival and may be considered as potentially curative RT PCR assay for detection of MRD should be regularly on post remission period as an important prognostic factor