This study was to investigate the presence of dopamine (DA) D 2receptors mRNA and binding sites in human amniotic epithelial cells (HAEC). RT–PCR revealed that HAEC express DA D 2receptor mRNA that is having 100 per cent homology with human DA D 2receptors. Radioligand saturation binding studies showed a [ 3H]YM-09151-2 high affinity binding site with a K Dand B maxvalues of 0.53±0.09 n m and 119.6±8.5 fmol/mg protein, respectively. Competition experiments demonstrated that selective D 2antagonists such as spiroperidol, domperidone and eticlopride potently competed with [ 3H]YM-09151-2 binding, whereas selective D 1antagonists like SCH 23390 displayed weaker competition for the binding sites. The rank order of potency of these compounds in competing with [ 3H]YM-09151-2 for the binding sites was consistent with the pharmacology of the DA D 2receptors. All competition curves were better fitted to a one-site model with a Hill coefficient around unity, indicating that [ 3H]YM-09151-2 is labelling a single population of receptors. These results provide evidence that HAEC natively express DA D 2receptor mRNA and binding sites. Although the physiological function of D2 receptors in HAEC is currently unclear, the present results suggest that these cells could represent a source of human DA D 2receptors without transformation or cloning procedures.