A mixture of cholera toxin conjugated HRP and WGA-HRP was injected into the posterior pituitary of the rat. The retrograde tracing technique was combined with immunohistochemistry to study the source of dopaminergic input to the posterior pituitary. Retrogradely labeled tyrosin hydroxylase-immunoreactive cells were found in the A14 dopaminergic cell group and the retrochiasmatic area. Scattered double labeled cells were also found in the ventral part of A 15.