The in vivo brain regional distribution of 2-[18F]fluoro-A-85380, a novel tracer for positron emission tomographic (PET) studies, followed the regional densities of brain nAChRs reported in the literature. Evidence of binding to nAChRs and high specificity of the binding in vivo was demonstrated by inhibition with nAChR selective ligands as well as with unlabeled 2-fluoro-A-85380. A preliminary toxicology study of the 2-fluoro-A-85380 showed a relatively low biological effect. 2-[18F]Fluoro-A-85380 holds promise as a useful radiotracer for imaging of nAChRs with PET.