We have evaluated the prostaglandin (PG) production and PG biosynthetic gene expression in a choriodecidual dispersed cell culture system. Cells dispersed from human choriodecidual membranes by dispase and trypsin digestion were evaluated after 1, 3, 5 and 7 days of culture for basal and tumour necrosis factor α (F-α) stimulated PGE2 production. The highest rates of production (P < 0.05) were obtained with cells treated after 3 days of culture, (3.7 ±1 ) × 102 pg PGE2 per 16 h per μg total cellular protein (mean ± SEM), which was 3.9 times basal rate after 3 days culture. In choriodecidual cells treated after 3 days in culture, expression of prostaglandin endoperoxide H synthase-2 (PGHS-2) mRNA was similarly responsive to TNF-α (3.9 times basal within 3 h of 30 ng/ml TNF-α) while there was little effect on PGHS-1 or cytosolic phospholipase A2 expression. Hence, the dispersed choriodecidual cell culture system described retains TNF-α responsive PG biosynthetic capacity which is at least in part upregulated via increased expression of PGHS-2 mRNA. © 2001 Harcourt Publishers Ltd.