[en] The tritiated dopamine reuptake inhibitor [³H]NNC 12-0781 (([1-[2-(bis(4-fluorophenyl)-methoxy)-ethyl]-4-(3-(2-furanyl)-2,3-[³H]- propyl)-piperazine) was radiolabelled in one step starting from 1-[2-(bis(4-fluorophenyl)-methoxy)-ethyl]-4-(3-(2-furanyl)-2-propenyl)- piperazine, using tritium gas and PdO as catalyst. The radiochemical purity of [³H]NNC 12-0781 was higher than 99% after HPLC purification with a specific radioactivity of 21 Ci/mmol. [³H]NNC 12-0781 bound specifically to rat striatum in vitro at +4 deg. C with a K_d of 1.76 nM andB_max of 587 fmol/mg tissue. The nonspecific binding was about 10% at K_d. At +37 deg. C no acceptable binding was observed. The association of [³H]NNC 12-0781 thus has the characteristics of a radioligand for the dopamine transporter in vitro at +4 deg. C