Numerous analogs of fatty acyl ethanolamides potentiate the intrinsic biological activity of arachidonoyl ethanolamide (anandamide; AEA). This potentiation is ascribed either to inhibition of AEA reuptake into neurons, or inhibition of fatty amide acyl hydrolase (FAAH) within the neurons. Oleoyl ethyl amide (OEtA) has potent FAAH inhibitory activity (IC 5.25 nM in rat brain homogenates) but does not inhibit acidic PEAase or bind to CB or CB receptors. OEtA is therefore a selective FAAH inhibitor with potential analgesic and anxiolytic activity.