We retrospectively analyzed 194 previously untreated acute myeloid leukemia (AML) patients to evaluate the role of Day 14 bone marrow (BM) biopsy in predicting complete remission (CR). Sixty-seven percent received induction therapy. Achieving Day 14 BM ≤5% blasts was strongly predictive of Day 28 CR with 90% sensitivity and 79% positive predictive value; but weak 43% specificity and 29% negative predictive value. Day 14 BM biopsy is highly sensitive in predicting CR, but did not predict overall survival. Some patients with BM blast >5% at Day 14 may still achieve a Day 28 CR, and not necessarily need reinduction therapy though high risk cytochemical or cytogenetic phenotype predicts a need for retreatment. Am. J. Hematol., 2008. © 2008 Wiley-Liss, Inc.