Repeated administrations of ethanol and of phenobarbital to rats led to characteristic withdrawal symptoms when the drug had been stopped. Since both drugs affect brain dopamine metabolism, the postjunctional sensitivity to dopamine in the corpora striata was tested during ethanol or phenobarbital withdrawal. This was done by studying the dopamine-sensitive adenylate cyclase in homogenates of the copora striata of ethanol- or phenobarbital-dependent rats. The results demonstrated a slight postjunctional subsensitivity to dopamine in withdrawal from both ethanol and phenobarbital. Both drugs, when added in vitro, did not affect the postjunctionsl sensitivity to dopamine. The results do not support the hypothesis, at least not in the case of dopamine, that a postjunctional supersensitivity to neurotransmitters is important for withdrawal symptoms after chronic administration of drugs inducing physical dependence.