In 71 adult acute myelogenous leukaemia (AML) cases, the relationship between well-known prognostic features and complete remission (CR) rate and survival was studied. These features were: (i) bone marrow karyotype classified NN, AN, AA according to Sakurai & Sandberg (5); (ii) patients' age; (iii) clinical 'negative prognostic features' (NPF): previous history of preleukaemia, septicaemia or pneumonia, hyperleucocytosis, associated pathology (diabetes, obesity, renal insufficiency etc.). 59 years of age was found to be a frontier between 2 homogeneous groups having quite different prognosis. The NN/AN/AA classification had good prognostic value (CR rate and survival) in patients under 59 years, but not in older patients. In those patients over 59, a significant difference in CR rate and survival appeared between cases with NPF and those without. For each feature having an established relationship to survival, a panel of prognostic points was determined as follows: age over 59 (1 point), AA karyotype in patients under 59 (2 points), NPF in patients over 59 (1 point). Using this stage classification, it was possible to classify every case into 1 of 3 groups (i.e.: 0 points, 1 point, 2 points). The life-table analysis of these 3 groups showed very significant differences. The median survival times were 18.5 months, 5.2 months and 1.3 month, for the 0-point group (26 cases), the 1-point group (19 cases) and the 2-point group (26 cases), respectively.