The purpose of our study was (i) to evaluate the impact of all-trans retinoic acid (ATRA) given as adjunct to chemotherapy and (ii) to compare second consolidation vs maintenance therapy in elderly patients with acute myeloid leukemia (AML). A total of 242 patients aged >or=61 years (median, 66.6 years) with AML were randomly assigned to ATRA beginning on day +3 after the initiation of chemotherapy (ATRA-arm, n=122) or no ATRA (standard-arm, n=120) in combination with induction and first consolidation therapy. A total of 61 patients in complete remission (CR) were randomly assigned to second intense consolidation (n=31) or 1-year oral maintenance therapy (n=30). After induction therapy the intention-to-treat analysis revealed a significant difference in CR rates between the ATRA- and the standard-arm (52 vs 39%; P=0.05). Event-free (EFS) and overall survival (OS) were significantly better in the ATRA-compared to the standard-arm (P=0.03 and 0.01, respectively). OS after second randomization was significantly better for patients assigned to intensive consolidation therapy (P<0.001). The multivariate model for survival revealed lactate dehydrogenase, cytogenetic risk group, age, and first and second randomization as prognostic variables. In conclusion, the addition of ATRA to induction and consolidation therapy may improve CR rate, EFS and OS in elderly patients with AML.