Acute promyelocytic leukemia (APL) is a subtype of AML that is a mixture of hematological malignancy, characterized by a specific translocation t(15;17). The using of all-trans retinoic acid (ATRA) with arsenic trioxide (ATO) or chemotherapeutic agents or both of these agents, composes main treatment strategy of APL. While it is possible to achieve success in treatment of low-risk APL with current treatment regimens, such success is not mentioned in high-risk APL. So, it may develop new approaches for treatment regimens for high-risk APL. In the present study, we aimed to investigate the effects of combinational of a classic anticancer agent paclitaxel and antidiabetic agent metformin on HL-60 APL cell line. The combination dose of paclitaxel and metformin was determined by WST-1 analysis. The effect of combinational dose on apoptosis was assessed in fluorescence microscope after using AnnexinV-EGFP Apoptosis and JC-1 Assay Kit. The effect of combinational dose on cell cycle, apoptosis and differentiation, and signaling pathways were determined investigating gene expression changes by using real time qRT-PCR. The combinational dose of paclitaxel and metformin was determined as 4.8 mu M and 398.7 mu M for 72 h, respectively. The combination dose significantly increased apoptosis for 48 h. In expression changes of genes associated cell cycle, apoptosis, cytokines, co-stimulator molecules, NF-kappa B and MAP/MAPK pathways, TLRs (Toll-like receptors) were found to be decreased or increased to provide apoptosis or differentiation. Consequently, we suggest that the combination of paclitaxel and metformin can be used as an option assessable for development of new treatment strategies for APL.