Endometrial and ovarian carcinomas are the most common malignancies of the female genital tract. Most of these neoplasms are associated with chromosomal abnormalities and show a constellation of rearrangements such as translocations, deletions, and inversions [1-5]. However, understanding of the molecular genetic and cyto genetic changes associated with ovarian tumor development and disease progression has been limited because of the extreme complexity of the abnormalities [2]. Cyto genetic abnormalities have diagnostic and prognostic value in ovarian carcinoma [2,5,6]. Some chromosomal breakpoints and fragile sites observed in cancer cases are accepted as cancer breakpoints and fragile sites [7,8]. Among the 30 gene-richest bands, cancer breakpoints and fragile sites colocalize at 1p36, 1q21, 7q22, 8q24, 11p15, 11q13, 11q23, 12q13, 16p13, and 19p13 [7,8]. Chromosome breakage is a manifestation of chromosomal instability. Chromosomal deletions in cancer cells are often found to contain tumor suppressor genes [7,8]. Structural rearrangements of chromosome arms 1p, 1q, 3p, 3q, 6q, 7p, 9q, 11p, 11q, 17q, 19p, and 19q were identified in ovarian tumors [1-3,5]. Taken together, these findings suggest that certain chromosomal abnormalities are important in the pathogenesis of ovarian and endometrial cancers. Because of this, we carried out cytogenetic analyses after short-term cultures of 23 endometrial and ovarian tumors. We here describe the chromosomal changes we found.