BACKGROUND. Acute myeloid leukemia (AML) with t(6;11)(q27;q23) is a well established but rare entity, and few studies have reported the full clinical, hematologic, and outcome data of patients with this disease. METHODS. To characterize the features of t(6;11) AML, the authors searched the Cancer and Leukemia Group B (CALGB) cytogenetic database comprising 2667 adults with newly diagnosed, de novo AML and identified 16 patients (0.6%) with t(6;11). A review of the literature identified 33 adults with de novo t(6;11) AML for whom survival data were available. RESULTS. CALGB patients had a median age of 45 years (range, 22-65 years) and commonly presented with French-American-British (FAB) subtype M4 or M5 (81%). Gingival involvement at presentation was common (31%). All patients with gingival involvement had FAB M4. Compared with other patients with M4 AML in the CALGB database (n = 429), patients with M4 and t(6;11) (n = 7) had a higher frequency of gingival hypertrophy at presentation (71% vs. 17%, P = 0.003). Patients with t(6;11) were more likely to be African American (P = 0.02) and to die during induction (P = 0.03) than those without t(6;11). The complete response (CR) rate was 69% (11 of 16 patients), and CR duration was short (median, 9 months). The estimated probability of 2-year survival was 13%. Both long-term survivors received allogeneic stem cell transplantation. The estimated probability of 2-year survival of patients reported in the literature was 15%. CONCLUSIONS. Although the patient sample was small, the authors suggested that investigational approaches, including allogeneic transplantation, be considered for adults with t(6;11) AML. © 2004 American Cancer Society.