We studied a group of 24 uterine and ovarian neoplasms with the purpose to verify if any correlation could be established between chromosomal abnormalities, loss of heterozigosity (LOH) and microsatellite instability (MIN). Tumor specimens obtained from 24 women (12 affected by ovarian and 12 by uterine neoplasms) were split in two parts, one was used for short term cultures for cytogenetic investigation while from the second DNA was extracted for molecular studies. We studied 22 polymorphic loci from 19 chromosomes and compared the alleles observed in the tumor with those observed in the DNA obtained from peripheral blood. Extensive loss of heterozigosity was observed when total or partial chromosomal loss was observed in at least 50% of the examined cells; MIN did not correlate with any particular cytogenetic abnormality nor with LOH.