2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to decrease rat adrenal 21-hydroxylase activity. It is thus suggested that TCDD might directly alter steroidogenesis in the adrenal cortical cells. The present study was designed to assess the direct effects of TCDD on basal and the agonist-stimulated aldosterone productions by bovine adrenal glomerulosa cells in vitro. Isolated bovine adrenal glomerulosa cells (1 x 105 cells/ml) were incubated with angiotensin II (AII: 10 nM), potassium chloride (4 mM and 8 mM), or ACTH (0.1 nM and 10 nM) in the absence (vehicle: 0.1 % DMSO) or presence of TCDD (from 1 pg/ml to 1 μg/ml) for 2 hours at 37 °C un­der 95 %O₂-5 %CO₂ gas. PCR was performed with a primer specific to aryl hydrocarbon receptor (AhR). In the present study, an expression of RT-PCR products amplified with AhR primers was detected in the cytosol from bovine adrenal glomerulosa cells. Basal and the agonist (AII, potassium, and ACTH)-stimulated aldosterone productions, however, did not alter in the presence of graded concentrations of TCDD in the incubation media. In conclusion, although the expression of AhR mRNA is recognized in bovine adrenal glomerulosa cells, it is suggested that the acute exposure at least less than 2 hours to TCDD does not alter the regulation of aldosterone production in bovine adrenal glomerulosa cells in vitro.