Objective To assess the clinical effectiveness and safety of inductive treatment with arsenic trioxide （As203） for acute promyelocytic leukemia （APL）. Methods Randomized controlled trials （RCTs） were identified from MEDLINE （1966 -July, 2005 ）, EMBASE （1984 -July, 2005 ）, The Cochrane Library （ Issue 3, 2005） and CBM- disc （1978 -July, 2005）. The references of eligible studies were handsearched. RCTs of As203 treating for APL were included. Data were evaluated and extracted by two reviewers independently with designed extraction form. RevMan 4. 2.7 software was used for data analysis. Results Six RCTs involving 323 patients were included. Two studies reported that there was no statistical difference between As2O3 group and all-transretinoic acid （ATRA） group in mortality for patients with APL or APL patients with complications of desseminated intiavascular coagulation or cerebra hemorrhage. The pooled result of 4 studies showed that there was no statistical difference with RR 0.98, 95 % CI 0.86 to 1.12 in complete remission （CR） rates between the two groups. The result of one study showed that the CR rate of patients with intravenous injection of As203 in 2 divided dosages with longer injection duration was higher with RR 1.31, 95% CI 0.86 to 1.12 compared with those with a single intravenous injection. Adverse effects in As2O3 group were less than ATRA group. Conclusions Inductive treatment with As2O3 for acute promyelocytic leukeuia has similar mortality and CR with less adverse effects compared with ATRA. More trials of high quality are required.