We analyzed 447 patients with de novo AML using alpha-satellite probes for the chromosomes 7, 8, X, and Y and RT-PCR for t(8;21), t(15;17) and inv(16). In 130/447 patients (29%) chromosomal aberrations were found. Thirty-three patients (7%) had a t(8;21); 11 of these had the additional loss of a sex chromosome (p<0.001) and two a trisomy 8. Twenty-nine patients (6%) had a t(15;17); four of these had a trisomy 8. Sixteen patients (4%) displayed an inv(16); four of these had a trisomy 8. Twenty-two patients (5%) had a sole trisomy 8 and one patient the combination of trisomy 8 and trisomy X. Five patients (1%) displayed the loss of a Y-chromosome as the sole abnormality and two patients had a sole trisomy X. In 22 patients (5%) a monosomy 7 was found, and in none of these patients were additional chromosomal aberrations detected by RT-PCR (p < 0.05). In conclusion, trisomy 8 and the loss of a gonosome are frequently associated with structural chromosomal aberrations with a significant association of -X/Y and t(8;21). The absence of these genomic lesions in AMLs with monosomy 7 suggests that the monosomy 7 has a specific role in the development of these leukemias and their clinical course.