OBJECTIVE To explore the significance of combined therapy of arsenic trioxide (As2O3) and all-trans retinoic acid (ATRA) in acute promyelocytic leukemia (APL). METHODS Retrospective study of 80 APL patients was performed and the complete remission (CR), the recovery time of peripheral hemoglobin and platelet, the early mortality, and the adverse reaction rates were analyzed between the ATRA group and the ATRA combined As2O3 group (combined group). RESULTS CR rate of the combined group and the ATRA group was 91.7% and 87.5% respectively, which showed no significant difference; time of reaching CR, hemoglobin recovery, and platelet recovery for the combined group were 28.0 +/- 7.8 days, 22.36 +/- 8.72 days and 19.38 +/- 9.52 days respectively, while those were 47.7 +/- 10.9 days, 28.40 +/- 8.95 days and 28.03 +/- 7.29 days for the ATRA group, which suggested a significantly shorter period of the combined group of achieving recovery. With 7.1% compared to 13.2%, the early mortality of the combined group seemed lower than that of the ATRA group but with no significance observed (P>0.05). The adverse reaction rates of the two groups also lacked any significant difference (P>0.05). CONCLUSION Compared with using ATRA alone, the combined therapy of AS2O3 and ATRA was dominant in achieving CR and recovery for APL. Besides, the combined therapy carries the promise of reducing the early mortality with no aggravation of the adverse reaction.