The aim of the study was to determine the correlation between the complexity of chromosome aberrations in ovarian cancer and its clinical stage and histological grade. 38 primary ovarian cancer tumors were analysed cytogenetically. The chromosomes were obtained from primary cell cultures in vitro and were stained using GTW technique. Advanced clinical stage correlated with complex chromosomal rearrangements. Similarly, histologically poorly differentiated tumors more often displayed complex chromosomal rearrangements (p = 0.004). Simple chromosome aberrations or normal karyotype were more frequently detected in well-differentiated tumors. The analysis of the results revealed that the increase in histological grade and clinical stage correlates with the increase in the number and complexity of chromosomal rearrangements.