Hereditary ovarian cancer accounts for about 5% to 10% of the total ovarian cancer bnurden, The discase has been observed in context with three types of hereditary ovarian cancer prone syndrome : (1) site-specific ovarian cancer, (2) hereditary breast/ivarian cancer syndrome, (3) hereditary nonpolyposis colorectal cancer(Lynch syndrome II). Each of these syndmmcs is chracterized by autosomal dominant transmission of cancer, sigrdficant early age of onset, and exeess of multiple Iprimary cancers. Auuthor expxeriencecl six families with hereditaty ovarian cancer, two families with a site-spxific. ovarian cancer and four with a breast/ovarian cancer syndrome, and report these families.