This study was undertaken to examine the effects of dioxin (TCDD) and nutrition on cellular proliferation and dioxin- and estrogen-linked gene expression in ovarian cancer cell lines. Caov-3 and SK-OV-3 cells were incubated in a medium supplemented with 0.5-10% fetal bovine serum (FBS). Cell proliferation was assayed with an MTT assay. Dioxin- and estrogen-linked genes (AhR, ERalpha, ERbeta, CYP1A1 and ARNT) expressed were determined with the RT-PCR method. Caov-3 cells, but not SK-OV-3 cells, were proliferated with TCDD alone with increased AhR and ERa mRNA expressions when incubated in the low FBS concentration. CYP1A1 and ARNT mRNA expressions of SK-OV-3, but not that of Caov-3, were suppressed in the low FBS (under 1.0%) concentration. In the low FBS concentration medium with dioxin, AhR and ERa expression were increased with the proliferation of Caov-3 cells; CYP1A1 and ARNT were stable. Each ovarian cancer cell line may have its own distinct responsiveness to dioxin depending on the nutritional state.