Cat superior cervical ganglia accumulated 14C-hemicholinium (HC-3), but the amount of drug taken up was not changed by nerve stimulation; accumulated HC-3 was not released by subsequent nerve stimulation. Choline and HC-3 were accumulated by a crude preparation of synaptosomes; the uptake of choline was blocked by HC-3, but the uptake of HC-3 was not blocked by choline. Choline, but not HC-3, was transported by red blood cells. It is concluded that HC-3 is not transported by the choline transport mechanism, and that in concentrations that are usually used in pharmacological experiments, HC-3 appears not to act as, or to form, a false cholinergic transmitter.