The objective of this study was to study the human ovarian cancer cell line CABA I by means of short tandem repeats (STR) profiling and cytogenetic analysis in order to prevent future misidentification or cross-contamination and verify its stability during in vitro cultivation. To this end, cells at passages 18 and 38 were analyzed using cytogenetic techniques in order to verify possible chromosomal aberrations and the karyotypic evolution of this cell line; GTG-banding and FISH were also performed. For STR analysis, DNA was extracted using the automated extractor MagNA pure and analyzed by means of PowerPlex 16 HS. STR profiles were analyzed by GeneMapper 3.2.1 software. Whereas comparative cytogenetic analysis of CABA I cells at passage 18 and 38 has demonstrated considerable genetic instability, we found that STR profiles were essentially unaltered in both analyzed passages, suggesting that the STR profile is reliable and could be used for the regular authentication of CABA I over time. It should be emphasized, however, that of the 16 loci generally used in human STR profiles, only 3 were properly detectable in CABA I. The data highlight that the CABA I cell line demonstrates an anomalous STR profile that does not fully adjust the criteria currently used for the identification of human cells; in spite of this, it remains stable during the in vitro maintainance. Moreover, the genetic instability of the CABA I cell line overlaps with those observed in vivo in tumor cells, making it a suitable candidate to analyze, in vitro, the peculiar genetic evolution of ovarian cancer cells.