The effects of the pyrimidinylpiperazinyl imide 846 (zalospirone), the substituted arylpiperazine WY-48,723, and the adamantyl piperazine derivative WY-50,324 were studied under punishment (conflict) procedures with pigeons to evaluate potential anxiolytic activity. These compounds were also studied in pigeons trained to discriminate administration of the serotonin (5-HT),, agonist 8-hydroxy-2-(di-n-propylamino) tetralin [8-OH-DPAT] (0.3 mg/kg) or buspirone (1 .O mg/kg), both administered i.m., from saline. All three compounds have high affinity for the 5-HTlA receptor site and WY-50,324 also has high affinity for 5-HT2 receptors, with activity as an antagonist at this site. Increases in punished responding occurred with all three drugs, with the magnitude of the increases in the order WY-50,324 > WY-48,723 > WY-47,846; increases with WY-50,324 reached almost 15,000% of control levels. Increases in punished responding occurred at doses that did not affect unpunished responding. Doses producing maximal effects of the three drugs were comparable (1 .O mg/kg), although WY-48,723 and WY-50,324 also produced large increases at doses as low as 0.1 mg/kg. All three drugs also substituted for 8-OH-DPAT and buspirone, with WY-48,723 and WY-50,324 producing complete substitution at 0.1-0.3