It has been proposed that the conditioned taste aversion paradigm may be used to achieve rapid training of subjects in drug discrimination studies. We report here that amphetamine (1.0 mg/kg) may acquire discriminative control over the preference of rats for a distinctive flavour when its administration precedes access to a saccharin solution (0.15% w/v), versus the occasions when the injection of saline precedes no toxicosis after access to the same flavour. Other doses of amphetamine (0.18-1.0 mg/kg) or apomorphine (0.1-1.0 mg/kg) produced a dose-dependent generalization to the stimulus cue of amphetamine (1.0 mg/kg), and haloperidol (0.01-0.1 mg/kg) was able to prevent the stimulus control exerted by amphetamine. No stimulus control was seen in a control group where no distinctive outcomes followed the administration of either amphetamine or saline before the subjects had access to the saccharin-flavoured solution. In the experimental group only, changes in the preference for saccharin were observed, with no changes in the total amount of water and saccharin ingested. Taken together, the present results suggest the usefulness of the conditioned taste aversion procedure to train subjects in drug discrimination.