[en] [¹⁸F]Benperidol ([¹⁸F]BP), a positron-emitting analogue of the dopaminergic D₂ antagonist benperidol, was evaluated as a radiopharmaceutical for use with positron emission tomography (PET). PET imaging of baboons after i.v. injection of [¹⁸F]BP indicated that the radiofluorinated ligand rapidly localized in vivo within dopaminergic receptor-rich cerebral tissues, and that selective disposition was retained for over 2 h. Pretreatment of an animal with unlabeled receptor-specific antagonists prior to injection of [¹⁸F]BP confirmed that the radioligand bound specifically to central D₂ receptors in vivo, and not to S₂ or D₁ receptors. [¹⁸F]BP bound to D₂ receptors in a reversible manner; unlabeled eticlopride displaced D₂ receptor-bound [¹⁸F]BP in vivo. The radioligand was metabolized in the periphery to polar metabolites which are not expected to cross the blood-brain barrier. [¹⁸F]BP has advantages over other tracers as a radiopharmaceutical for PET study of central D₂ receptor activity, and can be applied for noninvasive evaluation of the interaction of unlabeled drugs with central D₂ receptor sites