Five human ovarian carcinoma cell lines cultured from primary and metastatic tumors of Korean patients were characterized. These lines were isolated from two papillary serous cystadenocarcinomas, two endometrioid carcinomas, and one malignant Brenner tumor. It was shown that the growth of these cell lines was stable when cultured after at least 20 passages. Population doubling times varied from 40 to 67 hr. All lines showed high viability and were proven by DNA fingerprinting analysis to be unique. Contamination by mycoplasma or bacteria was excluded. In two lines, SNU-8 and SNU-840, an elevated level of CA125 antigen secretion could be detected, whereas CEA was undetectable in all five lines. Four different mutations in functional and highly conserved regions of the p53 gene were identified in three of our five lines (60%), namely in SNU-119, SNU-251, and SNU-563. Included were two missense mutations, one in-frame 3-base-pair deletion, and one out-of-frame 1-base-pair deletion. It is interesting to note that one of these three lines, SNU-251, presented an additional simultaneous nonsense mutation of the BRCA1 gene and missense mutation of the hMLH1 gene. In its lacking both wild-type alleles of the BRCA1 gene, SNU-251 might serve as an unusual and important in vitro model for studies related to ovarian carcinoma and the BRCA1 gene. It is thus likely that the establishment and characterization of these permanent human ovarian carcinoma cell lines in continuous cultures can provide useful tools for in vitro studies related to human ovarian carcinomas.