Summary Objectives: Impairments of apoptosis processes are the basis of pathogenesis of many diseases, including ovarian tumors. The aim of the study was to evaluated the concentration of soluble ligand for receptor CD30 (sCD30L) – marker of apoptosis in women with ovarian tumor. Material and methods: The study comprised 80 women, aged from 21 to 62, and included 30 patients with Cystadenocarcinoma serosum Ia, 35 with Cystadenoma serosum and 15 women with Teratoma maturum. The control group consisted of 30 healthy women, aged 24 to 57, with no evidence of pathological disorders in the reproductive system. The concentration of sCD30L in the serum of all studied women and in the fluid of ovarian cyst of women with cystadenoma serous were measured by immunoenzymatic method ELISA. Results: The highest level of sCD30L was observed in the serum of women with ovarian cancer and it was significantly higher when compared to the concentration in the serum of women with cystadenoma serous and teratoma maturum of the ovary (p<0.0001). In the fluid of ovarian cyst, the concentration of this marker was significantly higher in comparison with the level in the serum (p<0.0001). Conclusions: In women with ovarian tumors we observed impairments of the apoptosis process, which is associated with an increased concentration of sCD30L in the serum. These changes are more intense in women with ovarian cancer. Higher level of the study parameter in the fluid of ovarian cyst is associated with the local immune response suppression.