A novel serous surface papillary carcinoma of the ovary (SSPC) cell line, HYKSSPC, was established successfully. Carcinoma cells were obtained from ascitic fluid of a 60-year-old Japanese woman. The population doubling time was 51.4 h. A phase contrast micrograph showed a pavement stone-like arrangement without contact inhibition. The chromosome number showed a wide distribution of aneuploidy, and the mode was in 46-47. An immunocytochemical study showed that CA125, BerER4 and cytokeratin were positive and that CEA, calretinin and thrombomodulin were negative. This cell line preserved some characters of the adenocarcinoma while growing in vitro. A chemosensitivity test revealed that HYKSSPC cells were sensitive to CDDP (cis-platinum), 5-fluorouracil, mitomycin C, paclitaxel and irinotecan. To our knowledge, HYKSSPC is the first established cell line derived from SSPC, and it may offer some useful information for investigating this disease.