We aimed to study the effect of elapsed time from AML diagnosis to treatment (TDT) on OS in a group of patients from public Hospital in Brazil. 41 AML (23 M, 18 F, 41 yrs, 18 - 84 yrs, from 2001 to 2004). There were 38 de novo AML and 3 secondary, median TDT was 6 days (range 1 - 82 d); the young ones were treated earlier than old ones (TDT 4 days vs 11, p = 0.07). Longer TDT (>10 d) was associated with worse CR rates (p = 0.02) and OS (p = 0.04). When patients were categorized into TDT from 1 - 4 d (I) vs >5 (II), those from I presented better OS than II (p = 0.004). When TDT was longer than 7 days OS decreased even more. Hb was higher in patients with TDT I vs II (8.3 vs 7.5 g/dL, p = 0.03) but WBC (p = 0.34) and platelet count (p = 0.75) were not different. Patients with TDT of 10 d were younger than TDT > 10 d (median age 41 vs 70 yrs, p = 0.001). The OS was 15.1% in 2 yrs and 8.6% in 7 yrs. Our data suggest longer TDT, when analyzed continuously, predicted for lower CR rates and OS rates.