These studies examine whether αi-noradrenergic receptor stimulation alone is sufficient to facilitate lordosis behavior in ovariectomized, estrogen-primed female guinea pigs and to what extent α2-noradrenergic receptors are involved in this steroid-dependent behavior. Neither of the α1-agonists, phenylephrine or methoxamine, significantly facilitated lordosis in ovariectomized females primed with 10 µg of estradiol benzoate for 1 or 3 days. Animals exhibiting estrogen plus clonidine-facilitated lordosis showed a decrease in the behavior when given one of two α2-antagonists (yohimbine or idazoxan). Idazoxan also attenuated lordosis in animals given estrogen plus progesterone. These findings, in combination with previous findings (that specific α1-antagonists block lordosis), suggest that α2-receptors, in addition to α1-receptors play a role in modulation of lordosis b