In order to classlcaly condition the behavioural effects of psychomotor stimulants within a test context, rats were treated for 10 days with (+)-amphetamine (1.5 mg/kg), (+)-4-propyl-9-hydroxynaphthoxazine (PHNO, 30 μg/kg) or vehicle prior to a 1 h placement into a test box. Conditioned behavioural effects were then meaured in the previously drug-paired context after a vehicle injection (drug-free test day). Each rat was videotaped for the 1 h test box exposure on days 1,4,7 and 10 of the drug conditioning trials, and on the drug-free test day. Eleven of 28 behaviours that were scored for frequency, duration and mean bout duration (bout length) were significantly influenced by at least one of the two drugs. Amphetamine predominantly increased bout lengths while PHNO predominantly increased bout frequency. Only two measures that were influenced by the drugs exhibited dear increases over controls in a manner consistent with a classical conditioning teterpretation. Behavioural sensization clearly occurred to some of the effects of amphetamine and PHNO, but these were not the same effects as those increased on the non-drug day testing for classical conditioning. Most behavioural effects of amphetamine and PHNO are not classically conditioned, and behavioural sensitization to these drugs, while perhaps context-specific, is not due to classical conditioning. Automated measres of behaviours have provided misleading evidence concerning the similarity among behavioural effects of stimulants, sensitization and effects of exposure to an environment previously paired with stimulants-Analysis of transitons between behaviours does not support the view that stimulants increase switching or response competition, or that behavioural reorganization is responsible for sensitization. Rather, it is suggested that stimulants selectively facilitate current stimulus-guided behaviours.