Over the course of the last three decades it has become apparent that the majority of cases of acute myeloid leukemia (AML) are characterized by at least one of a variety of recurrent chromosomal abnormalities. Whilst in many instances it remains uncertain as to which abnormalities represent primary events in the pathogenesis of AML, those which provide critical second hits that are required for progression to full blown leukemia or those that are merely markers of the leukemic process, it is nevertheless clear that diagnostic karyotype is a key determinant of outcome in this disease. Indeed there is mounting evidence to support the notion that cytogenetic analysis can serve to identify biologically distinct subsets of AML that demand tailored therapeutic approaches. This underpins the trend towards more widespread adoption of routine cytogenetic and molecular analysis in the characterization of patients with a diagnosis of acute leukemia. A key challenge for the future is to use this information to achieve greater consensus in risk group assignment of AML which will provide a more reliable framework for determining the most appropriate treatment approach for individual patients with this disease.