The objective of this study for newly diagnosed acute promyelocytic Leukemia (APL) was to evaluate the efficacy of an intensified double induction chemotherapy including high dose ara-C (HD) and all-trans retinoic acid (ATRA) followed by consolidation and 3 years maintenance therapy. In contrast to APL studies stratifying therapy according to pretreatment white blood cell (WBC) count o and X10 Â 10 9 /l (low/intermediate and high risk according to the Sanz score), our patients received uniform therapy. From 1994 to 2005, 142 patients (age, 16-60 years) were enrolled. In the low/intermediate (n ¼ 105) vs high (n ¼ 37) WBC group, the rates of complete remission were 95.2 vs 83.8%, of induction death were 4.8 vs 16.2% (P ¼ 0.05) and of molecular remission were 87.5 vs 91.3% (P ¼ 1). Long-term overall survival was 84.4 vs 73.0% (P ¼ 0.12), event free survival was 78.3 vs 67.3% (P ¼ 0.11), relapse free survival was 82.1 vs 80.0% (P ¼ 0.83) and the cumulative incidence of relapse was 7.4 vs 11.4% (P ¼ 0.46). No relapse or death occurred after 4.7 years. ATRA and intensified chemotherapy including HD ara-C followed by prolonged maintenance therapy reduced the relapse risk in high risk patients. Pretreatment WBC count X10 Â 10 9 /l count was no relevant prognostic factor for relapse.