Acute myeloid leukaemia (AML) with the t(8;21)(q22;q22) is deemed to be a 'good-risk' disease. 396 patients with AML at diagnosis were screened for the presence of t(8;21) and AML1/ETO fusion transcripts by cytogenetic and RT-PCR techniques respectively. 32 cases of t(8;21) were detected, all of which were also PCR positive. A further 19 cases were detected at the molecular level, predominantly but not exclusively in M1 and M2 FAB types. Approximately 12% of all new cases of AML are estimated to have AML1/ETO fusion transcripts and it is suggested that molecular screening should be performed in all cases with the possible exception of the M3 FAB type.