6,3'-Dibromoflavone and 6-nitro-3'-bromoflavone inhibited [H-3]flunitrazepam binding to the benzodiazepine binding site of the gamma amino butyric acid receptor complex with K-i values between 17 and 36 nM in different brain regions. Their gamma amino butyric acid ratio for [H-3]flunitrazepam binding to cerebral cortex membranes indicated partial agonistic proper ties. Both compounds had similar pharmacological effects: they produced anxiolytic-like effects at low doses but did not alter locomotor activity or muscle tonicity; sedation was caused only at doses higher than 30 mg/kg in mice. These synthetic flavone derivatives join an existing family of 6,3'-disubstituted flavone compounds with high affinity for the benzodiazepine binding site and partial agonistic profiles.