An antibody against dopamine was raised in rabbits by means of an immunogen constituting dopamine coupled to bovine serum albumin by formaldehyde. These antibodies were applied to frozen sections of goldfish (Carassius auratus) brain fixed by 4% paraformaldehyde. The localization of immunoreactive structures corresponded to regions rich in dopamine detected by histofluorescence. The specificity of this antiserum, tested with the aid of dopamine analogs coupled with a carrying protein different from that of the antibody, indicates its validity as a method for the detection of dopaminergic neurons.